TYPO3 Core

Changelogs are really useful and often provide the best description of new features. But the information is quite fragmented and I think it would be useful, if we add more links to main documentation and possibly move some of the information from the changelog to the main documentation.

I'd like to do the following:

• Add links to main documentation
• Add links to related Changelog
• in some cases, move information from Changelog to main documentation

I am following the following concepts / best practices:

• Do not use absolute URLs, use intersphinx linking mechanism (`:ref:`)
• defragment
• deduplicate
• if possible, have one main entry point for a topic
• use links
• direct people to main source of documentation. For core information, this is usually "TYPO3 Explained" or one of the references.

Related (in docs):

• How to deal with Changelog becoming main documentation for some new features
• see also several issues on structure in project Content structure

Possible candidates:

• Important: #82692 - Guidelines for ext_localconf.php and ext_tables.php could link to TYPO3 Explained
• Site Handling could link to https://docs.typo3.org/typo3cms/CoreApiReference/ApiOverview/SiteHandling/Index.html