* 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

* polish some docs

* polish some docs

* Update square_cn.rst

* polish some docs

* polish some docs

* polish round docs

* polish round docs

* Update square_cn.rst

* polish some docs

* polish functional_cn.rst

* polish some docs

* polish some docs

* Update square_cn.rst

* polish some docs

* polish some docs

* polish round docs

* polish round docs

* Update square_cn.rst

* add mse_loss_cn doc

* add index

* add index

update the margin rank loss api doc

update demo code in NLLLoss_cn.rst

* add pairwise distance cn docs

* fix link

* add alias

* refine format

* fix doc tree

* fix format

* add name

* change out -> output

* change eps -> epsilon

* fix name

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

* fix MSELoss ch doc

* support pact demo load checkpoints

* fix example code

add CrossEntropyLoss cn doc

add upsample op's doc

* add paddle.nn.functional.interpolate doc
test=document_preview

* modified doc tree

* fix example,add annotation

* change order

* add doc of L1Loss, test=develop

* refine doc, test=develop

* add cn doc of trace API

* add cn doc of diag_embed API

* change cn.rst

* change cn.rst

* add api_cn

* test=develop

* add paddle.tensor

* add