Co-authored-by: Nwangchaochaohu <wangchao66@baidu.com>

* add float16 dtype, test=develop

* add type for unique

* add unique doc

* add cn for set_default_dtype/get_default_dtype/scatter/matmul

fix the doc of dot

 update the doc for the topK

* add unique doc

* add bernoulli

* refine manual_seed

* add bernoulli

* refine bernoulli

* refine squeeze

* refine unsqueeze

* refine stack

* fix manual_seed

* fix manual_seed

* Add chinese and english documents of paddle.prod

test=develop

 add doc of isnan, isinf, isfinite

* Add the argmax, argmin api doc for the api 2.0, test=develop

* add uniform op doc

* fix uniform en format

* delete useless code

* refine sign tanh api, test=develop

* Add Tanh, test=develop

* fix en, test=develop

* modify the doc, test=develop

* Update `paddle.clamp` doc

rename to `paddle.clip`
`input` -> `x`
remove `out`
update samples
wording: `Variable` - > `Tensor`

* Apply template

* Update `enable_imperative` -> `disable_static`

* Update sample: `to_tensor`

* modify the doc, test=develop

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

* update doc

* 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

* remove the out args

* polish sqrt doc

* Update sqrt_cn.rst

* Update sqrt_cn.rst

* Update sqrt_cn.rst

* Update `paddle.add` docs

remove `out` and `alpha`
explain broadcast semantics
update doc samples

* Apply template and fix alias