This patch adds a simple GitHub Actions workflow which will
automatically check open pull requests on code changes, adding a comment
and a label if the pull request has conflicts. The label will
automatically be removed again once the conflict has been resolved.

We use this for a while now with opencast and it really helps since
people do not have to manually check if their pull requests need an
update any longer.

An example, of hoe this looks in action can be found at
https://github.com/opencast/opencast/pull/2053#issuecomment-734987582

- Added config.yml for support sources outside of Github based on list from bigbluebutton.org
- Added comment to each issue template about this issue tracker not being for general support questions
- Deleted the general-issue.md template to try to steer support requests to the google groups/forums

Co-Authored-By: Anton Georgiev <antobinary@users.noreply.github.com>

This would be useful for get a notion from wich version it comes happening and which changes can causes the possible bugs.

Trying out issue template.