Added note about bootstrap version.

this commit breaks the apidoc extension. will adjust it afterwards.

Fixes #5467: Added ability to pass HTML tag options to `asEmail()`, `asImage()` and `asUrl()` methods of `yii\i18n\Formatter`

Fixes #4040: Added `$viewFile` and `$params` to the `EVENT_BEFORE_RENDER` and `EVENT_AFTER_RENDER` events for `View`.

Fixes #5232 and #5231

related to #5128

Fixes #4454: Improved asset bundle managed and used composer-asset-plugin to manage the dependencies on 3rd-party JS libraries

Fixes #4911: Changed callback signature used in `yii\base\ArrayableTrait::fields()` from `function ($field, $model) {` to `function ($model, $field) {`

Added note to config change

To get rid of confusions and errors. related to https://github.com/yiisoft/yii2/issues/4893

Fixes #4424: Added `inline` and `mimeType` options to all file downloading methods provided in `yii\web\Response`

Fixes #4489: RBAC PhpManager wasn't saving multiple assignmentsFixes #4489: RBAC PhpManager wasn't saving multiple assignments properly