Unify the guide content structure.

* fixed one error of api_cn

* fixed some errors of api_cn

* fixed some errors of api_cn

* fixed two errors.

* fixed two errors

* fixed one error.

* fixed one error

* fixed one error.

* fixed two errors.

* fixed one error.

* fixed two errors

* fixed two links

* synchronize api_cn with the api_en of develop.

* updated develop/api_cn

* update the api_cn of develop

* update api_cn of develop

* fixed some errors

* Delete .DS_Store

* Delete .DS_Store

* Delete .DS_Store

* Delete .DS_Store

* Delete .DS_Store

* fixed some wrong links

* fixed two links

* fixed two links and some error.

* fixed some errors.

* fixed two links

* http://newicafe.baidu.com/issue/DLTP-1771/show?from=page

* http://newicafe.baidu.com/issue/DLTP-1647/show?from=page

* http://newicafe.baidu.com/issue/DLTP-1529/show?from=page

* Update natural_exp_decay_cn.rst

* Update Reader_cn.rst

* http://newicafe.baidu.com/issue/DLTP-1907/show?from=page of develop

* documents will be ready afterwards

not ready now

* Update index_en.rst

* Update index_cn.rst

* Update index_en.rst

* Update index_cn.rst

* Update index_en.rst

* hotfix deadlink (#811)

* Update native_infer_en.md (#787)

* Update install_Windows_en.md (#790)

* Update install_Windows_en.md

* Update install_Windows_en.md

* Update cluster_howto_en.rst (#791)

* Update cluster_howto_en.rst

* Update cluster_howto_en.rst

* Update doc/fluid/user_guides/howto/training/cluster_howto_en.rst
Co-Authored-By: Nacosta123 <42226556+acosta123@users.noreply.github.com>

* Update doc/fluid/user_guides/howto/training/cluster_howto_en.rst
Co-Authored-By: Nacosta123 <42226556+acosta123@users.noreply.github.com>

* Update cluster_howto_en.rst

* Update index_cn.rst (#813)

* dygraph doc

* refine doc

* refine doc

* refine doc

* refine language

* refine code

* recheck_structure&fix_typo

* fix_structure

* adjust_dist_structure

* fix_deadlink

* fix deadlink