Add documentation link to extension information
Final goal: Render the link to docs in the extension manager's list. To achieve this, first the
extension.xml must be enhanced with a new field "documentation" which holds the URL just as e.g. in https://extensions.typo3.org/extension/news/
IMO this must be done on extensions.typo3.org as there already the fallback chain of Documentation/ > Readme.rst > Readme.md > external link > is known and rendered.
Once this is achieved we can improve the core
- Add a new property documentation_link to
extension.xmlwhich points to external documentation link or to the detail page of the extension