[Development] Qt 6.1.0 release note

[Jani Heikkinen]

Hi all,

Initial release note for Qt 6.1.0 here: https://code.qt.io/cgit/qt/qtreleasenotes.git/tree/qt/6.1.0/release-note.txt

Please review it and do needed modifications as a new change(s) in the release note repository: https://codereview.qt-project.org/admin/repos/qt/qtreleasenotes

Target is to release Qt 6.1.0 Thu 6th May and so on it would be good to have needed updates in before that. But of course updates after the release is also possible now when release notes are in their own repository.

br,
Jani