* refine bceloss doc

* fix doc

* fix name

* fix api 2.0 directory migration

* add dir file and change x to input

* add doc of loss function binary_cross_entropy.

* delete static demo code.

* add 2/3d adaptive_pooling

* fix format

* fix format

* add en doc rst

* fix format

* fix doc

* fix doc

* refine example code

* unify example code

* Udpate the doc format for the paddle, test=develop

* rename the inputs and update code example, test=develop

* update doc

* add mse_loss_cn doc

* add index

* add index

* test add api

* add_api test=develop

update the margin rank loss api doc

update demo code in NLLLoss_cn.rst

Update the docs of nn.loss.L1Loss and nn.functional.l1_loss

* Add the max, min, maximum, minimum api for the paddle 2.0

update the api doc for the cumsum op 

update the sort api, delete the unused index output

* Add fluid.rst

* fix cn rst

 Fix the compare ops doc for the api2.0

Fix the argsort, sort the api doc for paddle2.0

fix cross op doc for API2.0

* add English doc rst

* add chinese doc rst

* add chinese doc of new api(ReduceLROnPlatear)

* add chinese doc of new api(ReduceLROnPlatear)

* add chinese doc of new api(ReduceLROnPlatear)

* fix doc of ReduceLROnPlatear,test=develop

* fix description of mode

* fix doc of ReduceLROnPlatear,test=develop

Add new operator api: paddle.histc(input, bins=100, min=0, max=0)

Add paddle.framework.manual_seed ch doc

* add nn.* api

* test=develop

add paddle.complex.tensor.manipulation into gen_doc.sh