* Add Intro to JavaScript ES6 programming

* fix lint

* fix lint

* fix introducing to es6 to playlist link

* add GitHowTo

* fix lint

* adding 5 Chinese documents for Python.

* Sorry for the spelling mistake.

* Update free-programming-books.md

* Update free-programming-books.md

Sorry for the error, fixed the spaces so that the linting will now work.

* Update free-programming-books-zh.md

* Update free-programming-books-zh.md

Added author name
Co-Authored-By: Nstacklens <474377974@qq.com>

* Update free-courses-pt_BR.md

* Update free-courses-pt_BR.md

* Create free-courses-pt_BR.md

WIP

* Update free-courses-pt_BR.md

* Update free-courses-pt_BR.md

* Update README.md

* delete dead link and remove `required` a WEIBO Account

* remove dead ref link.

* Format desc of zh version programming books base on CONTRIBUTING-zh.

* optimize zh version book comments.

* Fix Travis CI check.

* Commit update for suggestion of [zhongjiajie]

* Learn Azure in a Month of Lunches Book Added

* Learn Azure in a Month of Lunches Book Added

* Author Added

* Update CONTRIBUTING-zh file: format MD desc and refine the essay.

* Fix incorrect md syntax.

* Refine the zh CONTRIBUTING essay.

* update formatting

* Fix Travis CI check

* Update incorrect formatting

* Update formatting

* fix travis-ci issue