PaddlePaddle.org requires the nav tree to be generated in order to parse the...

PaddlePaddle.org requires the nav tree to be generated in order to parse the site map.  Since we removed theme in https://github.com/PaddlePaddle/Paddle/pull/8752, this also removed the site navigation menu.  This changelist adds back the site navigation menu. (#8760)

doc/templates/conf.py.cn.in

@@ -22,6 +22,11 @@ import paddle.v2
 MarkdownParser = parser.CommonMarkParser
 AutoStructify = transform.AutoStructify
 
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+templates_path = ["@PADDLE_SOURCE_DIR@/doc/templates"]
+
 # -- General configuration ------------------------------------------------
 
 # General information about the project.

doc/templates/conf.py.en.in

@@ -23,6 +23,11 @@ import paddle.v2
 MarkdownParser = parser.CommonMarkParser
 AutoStructify = transform.AutoStructify
 
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+templates_path = ["@PADDLE_SOURCE_DIR@/doc/templates"]
+
 # -- General configuration ------------------------------------------------
 
 # General information about the project.

doc/templates/layout.html

@@ -2,6 +2,13 @@
 {# Import the theme's layout. #}
 {% extends "!layout.html" %}
 
+{# SIDE NAV, TOGGLES ON MOBILE #}		
+{% block menu %}
+<nav class="doc-menu-vertical" role="navigation">
+{% set toctree = toctree(maxdepth=-1, collapse=False,titles_only=True, includehidden=True) %}
+{{ toctree }}
+</nav>
+{% endblock %}
 
 {%- block extrahead %} 
 <script>