adjust mkdocs config & refine distillation doc

docs/docs/api/single_distiller_api.md

-# paddleslim.dist API文档
+## merge
+paddleslim.dist.merge(teacher_program, student_program, data_name_map, place, scope=fluid.global_scope(), name_prefix='teacher_') [[源代码]](https://github.com/PaddlePaddle/PaddleSlim/blob/develop/paddleslim/dist/single_distiller.py#L19) 
 
-## merge(teacher_program, student_program, data_name_map, place, scope=fluid.global_scope(), name_prefix='teacher_')
-
-该方法将两个fluid program（teacher_program, student_program）融合为一个program，并将融合得到的program返回。在融合的program中，可以为其中合适的teacher特征图和student特征图添加蒸馏损失函数，从而达到用teacher模型的暗知识（Dark Knowledge）指导student模型学习的目的。
+: merge将两个paddle program（teacher_program, student_program）融合为一个program，并将融合得到的program返回。在融合的program中，可以为其中合适的teacher特征图和student特征图添加蒸馏损失函数，从而达到用teacher模型的暗知识（Dark Knowledge）指导student模型学习的目的。
 
 **参数：**
 
-- **teacher_program**(Program)-定义了teacher模型的paddle program
-- **student_program**(Program)-定义了student模型的paddle program
-- **data_name_map**(dict)-teacher输入接口名与student输入接口名的映射，key为teacher的输入名，value为student的输入名。merge函数将会把这两个模型的输入按对应关系合并在一起，保证teacher与student输入数据相同
+- **teacher_program**(Program)-定义了teacher模型的 [*paddle program*](https://www.paddlepaddle.org.cn/documentation/docs/zh/api_cn/fluid_cn/Program_cn.html#program)
+- **student_program**(Program)-定义了student模型的 [*paddle program*](https://www.paddlepaddle.org.cn/documentation/docs/zh/api_cn/fluid_cn/Program_cn.html#program)
+- **data_name_map**(dict)-teacher输入接口名与student输入接口名的映射，其中dict的 *key* 为teacher的输入名，*value* 为student的输入名
 - **place**(fluid.CPUPlace()|fluid.CUDAPlace(N))-该参数表示程序运行在何种设备上，这里的N为GPU对应的ID
-- **scope**(Scope)-该参数表示teacher variables和student variables所使用的作用域，如果不指定将使用默认的全局作用域。默认值：fluid.global_scope()
-- **name_prefix**(str)-为了避免teacher variables和student variables存在同名变量而引起命名冲突，merge函数将统一为teacher variables添加一个名称前缀name_prefix，merge后的program中所有teacher variables都将带有这一名称前缀。默认值：'teacher_'
+- **scope**(Scope)-该参数表示程序使用的变量作用域，如果不指定将使用默认的全局作用域。默认值：[*fluid.global_scope()*](https://www.paddlepaddle.org.cn/documentation/docs/zh/api_cn/fluid_cn/global_scope_cn.html#global-scope)
+- **name_prefix**(str)-merge操作将统一为teacher的[*Variables*](https://www.paddlepaddle.org.cn/documentation/docs/zh/1.3/api_guides/low_level/program.html#variable)添加的名称前缀name_prefix。默认值：'teacher_'
+
+**返回：** 由student_program和teacher_program merge得到的program
+
+!!! note "Note"
+    *data_name_map* 是 **teacher_var name到student_var name的映射**，如果写反可能无法正确进行merge
 
-**返回：**由student_program和teacher_program merge得到的program
 
 **使用示例：**
 
-```python
+```python hl_lines="17 18"
 import paddle.fluid as fluid
 import paddleslim.dist as dist
 student_program = fluid.Program()
@@ -34,14 +37,15 @@ with fluid.program_guard(teacher_program):
 data_name_map = {'y':'x'}
 USE_GPU = False
 place = fluid.CUDAPlace(0) if USE_GPU else fluid.CPUPlace()
-main_program = dist.merge(teacher_program, student_program, data_name_map, place)
+main_program = dist.merge(teacher_program, student_program,
+		                  data_name_map, place)
 ```
 
 
+## fsp_loss
+paddleslim.dist.fsp_loss(teacher_var1_name, teacher_var2_name, student_var1_name, student_var2_name, program=fluid.default_main_program()) [[源代码]](https://github.com/PaddlePaddle/PaddleSlim/blob/develop/paddleslim/dist/single_distiller.py#L90)
 
-## fsp_loss(teacher_var1_name, teacher_var2_name, student_var1_name, student_var2_name, program=fluid.default_main_program())
-
-fsp_loss为program内的teacher var和student var添加fsp loss，出自论文[A Gift from Knowledge Distillation: Fast Optimization, Network Minimization and Transfer Learning](http://openaccess.thecvf.com/content_cvpr_2017/papers/Yim_A_Gift_From_CVPR_2017_paper.pdf)
+: fsp_loss为program内的teacher var和student var添加fsp loss，出自论文[<<A Gift from Knowledge Distillation: Fast Optimization, Network Minimization and Transfer Learning\>\>](http://openaccess.thecvf.com/content_cvpr_2017/papers/Yim_A_Gift_From_CVPR_2017_paper.pdf)
 
 **参数：**
 
@@ -49,13 +53,13 @@ fsp_loss为program内的teacher var和student var添加fsp loss，出自论文[A
 - **teacher_var2_name**(str): teacher_var2的名称. 对应的variable是一个形为`[batch_size, y_channel, height, width]`的4-D特征图Tensor，数据类型为float32或float64。只有y_channel可以与teacher_var1的x_channel不同，其他维度必须与teacher_var1相同
 - **student_var1_name**(str): student_var1的名称. 对应的variable需与teacher_var1尺寸保持一致，是一个形为`[batch_size, x_channel, height, width]`的4-D特征图Tensor，数据类型为float32或float64
 - **student_var2_name**(str): student_var2的名称. 对应的variable需与teacher_var2尺寸保持一致，是一个形为`[batch_size, y_channel, height, width]`的4-D特征图Tensor，数据类型为float32或float64。只有y_channel可以与student_var1的x_channel不同，其他维度必须与student_var1相同
-- **program**(Program): 用于蒸馏训练的fluid program。默认值：fluid.default_main_program()
+- **program**(Program): 用于蒸馏训练的fluid program。默认值：[*fluid.default_main_program()*](https://www.paddlepaddle.org.cn/documentation/docs/zh/1.3/api_cn/fluid_cn.html#default-main-program)
 
-**返回：**由teacher_var1, teacher_var2, student_var1, student_var2组合得到的fsp_loss
+**返回：** 由teacher_var1, teacher_var2, student_var1, student_var2组合得到的fsp_loss
 
 **使用示例：**
 
-```python
+```python hl_lines="19 20"
 import paddle.fluid as fluid
 import paddleslim.dist as dist
 student_program = fluid.Program()
@@ -74,26 +78,28 @@ USE_GPU = False
 place = fluid.CUDAPlace(0) if USE_GPU else fluid.CPUPlace()
 main_program = merge(teacher_program, student_program, data_name_map, place)
 with fluid.program_guard(main_program):
-    distillation_loss = dist.fsp_loss('teacher_t1.tmp_1', 'teacher_t2.tmp_1', 's1.tmp_1', 's2.tmp_1', main_program)
+    distillation_loss = dist.fsp_loss('teacher_t1.tmp_1', 'teacher_t2.tmp_1',
+			                          's1.tmp_1', 's2.tmp_1', main_program)
 ```
 
 
 
-## l2_loss(teacher_var_name, student_var_name, program=fluid.default_main_program())
+## l2_loss
+paddleslim.dist.l2_loss(teacher_var_name, student_var_name, program=fluid.default_main_program())[[源代码]](https://github.com/PaddlePaddle/PaddleSlim/blob/develop/paddleslim/dist/single_distiller.py#L118)
 
-l2_loss为program内的teacher var和student var添加l2 loss
+: l2_loss为program内的teacher var和student var添加l2 loss
 
 **参数：**
 
 - **teacher_var_name**(str): teacher_var的名称. 
 - **student_var_name**(str): student_var的名称.
-- **program**(Program): 用于蒸馏训练的fluid program。默认值：fluid.default_main_program()
+- **program**(Program): 用于蒸馏训练的fluid program。默认值：[*fluid.default_main_program()*](https://www.paddlepaddle.org.cn/documentation/docs/zh/1.3/api_cn/fluid_cn.html#default-main-program)
 
-**返回：**由teacher_var, student_var组合得到的l2_loss
+**返回：** 由teacher_var, student_var组合得到的l2_loss
 
 **使用示例：**
 
-```python
+```python hl_lines="19 20"
 import paddle.fluid as fluid
 import paddleslim.dist as dist
 student_program = fluid.Program()
@@ -112,28 +118,30 @@ USE_GPU = False
 place = fluid.CUDAPlace(0) if USE_GPU else fluid.CPUPlace()
 main_program = merge(teacher_program, student_program, data_name_map, place)
 with fluid.program_guard(main_program):
-    distillation_loss = dist.l2_loss('teacher_t2.tmp_1', 's2.tmp_1', main_program)
+    distillation_loss = dist.l2_loss('teacher_t2.tmp_1', 's2.tmp_1',
+			                         main_program)
 ```
 
 
 
-## soft_label_loss(teacher_var_name, student_var_name, program=fluid.default_main_program(), teacher_temperature=1., student_temperature=1.)
+## soft_label_loss
+paddleslim.dist.soft_label_loss(teacher_var_name, student_var_name, program=fluid.default_main_program(), teacher_temperature=1., student_temperature=1.)[[源代码]](https://github.com/PaddlePaddle/PaddleSlim/blob/develop/paddleslim/dist/single_distiller.py#L136)
 
-soft_label_loss为program内的teacher var和student var添加soft label loss，出自论文[Distilling the Knowledge in a Neural Network](https://arxiv.org/pdf/1503.02531.pdf)
+: soft_label_loss为program内的teacher var和student var添加soft label loss，出自论文[<<Distilling the Knowledge in a Neural Network\>\>](https://arxiv.org/pdf/1503.02531.pdf)
 
 **参数：**
 
 - **teacher_var_name**(str): teacher_var的名称. 
 - **student_var_name**(str): student_var的名称. 
-- **program**(Program): 用于蒸馏训练的fluid program。默认值：fluid.default_main_program()
+- **program**(Program): 用于蒸馏训练的fluid program。默认值：[*fluid.default_main_program()*](https://www.paddlepaddle.org.cn/documentation/docs/zh/1.3/api_cn/fluid_cn.html#default-main-program)
 - **teacher_temperature**(float): 对teacher_var进行soft操作的温度值，温度值越大得到的特征图越平滑 
 - **student_temperature**(float): 对student_var进行soft操作的温度值，温度值越大得到的特征图越平滑 
 
-**返回：**由teacher_var, student_var组合得到的soft_label_loss
+**返回：** 由teacher_var, student_var组合得到的soft_label_loss
 
 **使用示例：**
 
-```python
+```python hl_lines="19 20"
 import paddle.fluid as fluid
 import paddleslim.dist as dist
 student_program = fluid.Program()
@@ -152,26 +160,28 @@ USE_GPU = False
 place = fluid.CUDAPlace(0) if USE_GPU else fluid.CPUPlace()
 main_program = merge(teacher_program, student_program, data_name_map, place)
 with fluid.program_guard(main_program):
-    distillation_loss = dist.soft_label_loss('teacher_t2.tmp_1', 's2.tmp_1', main_program, 1., 1.)
+    distillation_loss = dist.soft_label_loss('teacher_t2.tmp_1',
+			                                 's2.tmp_1', main_program, 1., 1.)
 ```
 
 
 
-## loss(loss_func, program=fluid.default_main_program(), **kwargs)
+## loss
+paddleslim.dist.loss(loss_func, program=fluid.default_main_program(), **kwargs) [[源代码]](https://github.com/PaddlePaddle/PaddleSlim/blob/develop/paddleslim/dist/single_distiller.py#L165)
 
-loss函数支持对任意多对teacher_var和student_var使用自定义损失函数
+: loss函数支持对任意多对teacher_var和student_var使用自定义损失函数
 
 **参数：**
 
 - **loss_func**(python function): 自定义的损失函数，输入为teacher var和student var，输出为自定义的loss 
-- **program**(Program): 用于蒸馏训练的fluid program。默认值：fluid.default_main_program()
+- **program**(Program): 用于蒸馏训练的fluid program。默认值：[*fluid.default_main_program()*](https://www.paddlepaddle.org.cn/documentation/docs/zh/1.3/api_cn/fluid_cn.html#default-main-program)
 - **\**kwargs**: loss_func输入名与对应variable名称
 
 **返回**：自定义的损失函数loss
 
 **使用示例：**
 
-```python
+```python hl_lines="24 25"
 import paddle.fluid as fluid
 import paddleslim.dist as dist
 student_program = fluid.Program()
@@ -195,12 +205,12 @@ def adaptation_loss(t_var, s_var):
     hint_loss = fluid.layers.reduce_mean(fluid.layers.square(s_hint - t_var))
     return hint_loss
 with fluid.program_guard(main_program):
-    distillation_loss = dist.loss(main_program, adaptation_loss, t_var='teacher_t2.tmp_1', s_var='s2.tmp_1')
+    distillation_loss = dist.loss(main_program, adaptation_loss,
+			t_var='teacher_t2.tmp_1', s_var='s2.tmp_1')
 ```
 
-## 注意事项
-
-在添加蒸馏loss时会引入新的variable，需要注意新引入的variable不要与student variables命名冲突。这里建议两种用法：
+!!! note "注意事项"
+    在添加蒸馏loss时会引入新的variable，需要注意新引入的variable不要与student variables命名冲突。这里建议两种用法（两种方法任选其一即可）：
 
-1. 建议与student_program使用同一个命名空间，以避免一些未指定名称的variables(例如tmp_0, tmp_1...)多次定义为同一名称出现命名冲突
-2. 建议在添加蒸馏loss时指定一个命名空间前缀，具体用法请参考Paddle官方文档[fluid.name_scope](https://www.paddlepaddle.org.cn/documentation/docs/zh/api_cn/fluid_cn/name_scope_cn.html#name-scope)
+    1. 建议与student_program使用同一个命名空间，以避免一些未指定名称的variables(例如tmp_0, tmp_1...)多次定义为同一名称出现命名冲突
+    2. 建议在添加蒸馏loss时指定一个命名空间前缀，具体用法请参考Paddle官方文档[*fluid.name_scope*](https://www.paddlepaddle.org.cn/documentation/docs/zh/api_cn/fluid_cn/name_scope_cn.html#name-scope)

docs/mkdocs.yml

 site_name: PaddleSlim Docs
+repo_url: https://github.com/PaddlePaddle/PaddleSlim
 nav:
 - Home: index.md
 - 教程:
@@ -14,12 +15,33 @@ nav:
   - SA搜索: api/nas_api.md
   - 搜索空间: api/search_space.md
 
-theme: readthedocs
+theme:
+    name: readthedocs
+    highlightjs: true
 
 markdown_extensions:
-  - pymdownx.arithmatex
   - admonition
-  - codehilite
+  - codehilite:
+      guess_lang: true
+      linenums: true
+  - toc:
+      permalink: "#"
+  - footnotes
+  - meta
+  - def_list
+  - pymdownx.arithmatex
+  - pymdownx.betterem:
+      smart_enable: all
+  - pymdownx.caret
+  - pymdownx.critic
+  - pymdownx.details
+  - pymdownx.magiclink
+  - pymdownx.mark
+  - pymdownx.smartsymbols
+  - pymdownx.superfences
+  - pymdownx.tasklist
+  - pymdownx.tilde
+
 extra_javascript:
   - mathjax-config.js
   - MathJax.js?config=TeX-AMS-MML_HTMLorMML