create new doc for nn.functional.one_hot

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