Extensions: Link from description to relevant section in the manual

The new Extension mode in Qt Creator features a high-level description of the plugins functionality.

For plugins where it makes sense, it would be great to link to the matching functionality description in the documentation, either in Qt Creator itself (help mode) or the online manual.

E.g.

RemoteLinux Plugin -> https://doc.qt.io/qtcreator/creator-developing-generic-linux.html