Chinese guide

Conflicts:
	docs/guide-zh-CN/intro-yii.md

Merge branch 'widgets-activeform-incorrect-js-selector' of github.com:creocoder/yii2 into creocoder-widgets-activeform-incorrect-js-selector

Conflicts:
	framework/CHANGELOG.md

BootstrapThemeAsset comment fix

structure applications guide translated

French intro-upgrade-from-v1

Fix links [skip ci]

Spanish traduction for start-hello.md guide

* 'temp' of https://github.com/klevron/yii2:
  Links fix [skip ci]
  Models link fix [skip ci]
  Install link fix [skip ci]

Conflicts:
	docs/guide/intro-upgrade-from-v1.md

Fix typo [skip ci]

Fix assets links [skip ci]

Fixes #3358: Removed automatic CSRF meta tag generation by `View`. Added `Html::csrfMetaTags()` and its call to main layout files