TYPO3 Core

Site Settings were introduced with TYPO3 v10.

In order to separate settings, make them accessible and editable in the TYPO3 Backend, and distinguish between the functionality between required site configuration and optional settings, the "settings" part of the settings are moved to a separate "settings.yaml" file in the site configuration folder, which will later-on be editable by the TYPO3 Backend
with the new Settings API introduced in a separate patch.