proof translation and fix the link for Chinese translation [skip ci]

Update CHANGELOG.md

We need an image of the CRUD preview (or we need to change the text).

Not clear how define('YII_ENV', 'dev') creates the YII_ENV_DEV
constant. Seems like an odd bit of magic that may confuse others…

Should it be “quality of these articles may not be as good”?

Spanish guide structure-application-components.md [skip ci]

Application templates refactoring

[ci skip]

intro upgrade from v1 guide translated

Create caching-page.md

French start-installation.md

Fix typo in start-installation.md