Should have started this before; important to maintain consistency.

[ci skip]

Catalan translation

No major changes. Looks good!

Update concept-behaviors.md

fixed spelling

Fixed document for multisort in BaseArrayHelper

Fixed

Lithuanian translation

[ci skip] Update Generator.php

To comply with the docs RE namespace usage:
https://github.com/yiisoft/yii2/blob/master/docs/guide/extend-creating-extensions.md

[ci skip] Update concept-service-locator.md

[ci skip] Fixes example code symbol errors