Moving development related discussion to Github

In one of the last weekly developer meeting an interesting idea came up which was to move board development related discussions from forums to Github.

The reasons @SteeManMI, @igorpecovnik and @rpardini pointed out are that development itself happens on Github anyways, developers most likely have a Github account but not a forum account and also may not want to create one. This increases our chances to attract new developers.
Also linking issues and proper formatting is present in Github while not in forums.

Therefore the suggestions is to enable the Github discussions feature (https://docs.github.com/de/discussions) for the build repository and set the current "board bring up" forums to read-only with a hint about this change.

What structure should Github discussion have?
As for myself I think a single "forum" is enough to replace current one in Community forums.
Also there was the question about the necessity of moderation then where I think this won't be an issue.

Suggestions or objections? @armbian/board-maintainers

Corresponding meeting: https://forum.armbian.com/topic/25730-armbian-developers-meeting-1112023/#comment-157588