* api modification

half modification of fluid/io/layers

* Apply suggestions from code review
Co-Authored-By: Nzy0531 <48094155+zy0531@users.noreply.github.com>

* Update fluid_cn.rst

* api_trans_0410

* Update io_cn.rst

* Apply suggestions from code review

* fix bugs

* routine bug fix

* update text info

* fix io_cn all

* 持久性变量=>长期变量

* debug

* fix 2 -conv2d

* "锚" ==> anchor(s)

* delete en2zn link

* 1207

 1.english api reference links removed
2. formatted

* update transpiler

* update profilse_cn

 1.english api reference links removed
2. formatted

* add_api_cn (#437)

* add gpu benchmark page (#436)

* add gpu benchmark

* fix comments

* add chinese link in gen_doc.py (#439)

* modified gen_doc.py

* Update gen_doc.py

* update gen_doc.py

* Update mobile doc (#440)

* update_en_structure

* update_Paddle_commitid

* delete_DS

* update_mobile_doc

* Update book commit (#438)

* update_en_structure

* update_Paddle_commitid

* delete_DS

* update_book_commit_id

* update_api_rst

* Adjust structure of advanced usage (#442)

* adjust_structure_of_advanced_usage

* Update paddle_gpu_benchmark.md

* adjust_toctree_hidden

* fix_api_guide

* Update index.rst

* fix deadlinkes (#443)

* add_toctree (#445)

* adjust_beginners_structure (#446)

* adjust_beginners_structure

* Update index.rst

* update install_doc for python3 (#418)

* update install_doc for python3

* update python3.5+ info,test=develop

* fix review, test=develop

* fix_pic (#447)