Translate some chapters to [Jul 17, 2020] Part-6 (#795) (#804)

* Minor error fix in 1-js/05-data-types/02-number/article.md

* Translated 2-ui/3-event-details/6-pointer-events

* Translated some chapters to [Jul 17, 2020] Part-6 #795

* Translation improvement

* Minor error fix in 1-js/05-data-types/02-number/article.md

* Minor fix in 2-ui/3-event-details/1-mouse-events-basics

* Minor fix in 2-ui/3-event-details/1-mouse-events-basics

* Update 2-ui/1-document/01-browser-environment/article.md

Co-authored-by: Martin <a545067127@outlook.com>

* Apply suggestions from code review

Co-authored-by: Martin <a545067127@outlook.com>

* Apply suggestions from code review

Took some suggestions

Co-authored-by: Martin <a545067127@outlook.com>

* Apply suggestions from code review

Commit from suggestions

Co-authored-by: Martin <a545067127@outlook.com>

* Apply suggestions from code review

Commit from suggestion

Co-authored-by: bemself <45781328+bemself@users.noreply.github.com>

* Update 2-ui/3-event-details/6-pointer-events/article.md

Co-authored-by: bemself <45781328+bemself@users.noreply.github.com>

* Apply suggestions from code review

已补充 commit。

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* Update article.md

* Update article.md

* Update article.md

* Update index.html

* Update article.md

* Update article.md

* Update article.md

* Update article.md

* Update article.md

* Update article.md

Co-authored-by: Martin <a545067127@outlook.com>
Co-authored-by: bemself <45781328+bemself@users.noreply.github.com>
Co-authored-by: LeviDing <imdingxuewen@gmail.com>