* add_three_args

* add broadcasting index and some common args text=develop

* fix broadcasting index test=develop

* fix broadcasting test=develop

* update dygraph doc; test=develop

* change dygraph to imperative; test=develop

* move impertive to beginer guid; test=develop

This reverts commit 685da70d.

* add hap readme, test=develop

* add hap readme, test=develop

test=document_fix

* add cn docs, test=develop

* refine docs, test=develop

* add program doc, test=develop

* fix links, test=develop

* fix links, test=develop

* fix links, test=develop

* fix links, test=develop

* Fluid -> Paddle, test=develop

* Fluid -> Paddle, test=develop

* minor fix, test=develop

* minor fix, test=develop

Unify the guide content structure.

* 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)

* adjust_beginners_structure

* Update index.rst