docs about file validator fixed

Spanish guide polish and start-looking-head.md [skip ci]

to be adjusted while translating chapters.

type validation adjusted

Fix in start-hello.md and spanish translation of start-forms.md

Create db-active-record.md

Create db-dao.md

暂未校对

Spanish translation of start-forms.md

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]