* Add usage manual for VisualDL
The usage manual will be helpful for beginners to make use of VisualDL.

Components of VisualDL are introduced in details, including:
	* Definition of Functions
	* Parameters explanation
	* Demo program for each component

* add_index

* synchronize with develop (#642)

* update_commitid1.3 (#641)

* update inference c++ API doc (#634)

* update inference c++ API doc

* fix link

* thorough clean for doc (#644)

* thorough clean

* delete_DS_Store

* Cherrypick1.3 (#652)

* thorough clean

* delete_DS_Store

* [Don't merge now]update_install_doc (#643)

* update_install_doc

* follow_comments

* add maxdepth (#646)

* upload_md (#649)

* update_version (#650)

* Translation of 16 new apis (#651)

* fix_windows

* Final update 1.3 (#653)

* thorough clean

* delete_DS_Store

* update_1.3

* Deadlink fix (#654)

* fix_deadlinks

* update_docker

* Update release_note.rst

* Update index_cn.rst

* update_Paddle (#658)

* fix pic (#659)

* [to 1.3] cn api debug (#655) (#661)

* debug

* fix 2 -conv2d

* "锚" ==> anchor(s)