Prioritize github issue

I open this new discussion because we have a lot of open issues on github and "pick up the one you want to" seems not the more efficient way to work on diaspora*.

So I think we should try to order issues, saying "this one should be solved before this one". Of course, this is not a blocker, if someone opens a PR fixing a low priority issue, we will still accept it.

So, how do we want to prioritize issues? We have many different labels. "Bug", "regression", "confirmed"... and also milestones. Maybe we can set milestones on more issues to say we want to see that solved, and delay the milestone to the next same-type release if the issue is not solved?

For example, #4757 is a critical issue to me. We could set the "next-minor" milestone on it. If nobody solves it and the date to release the next-minor is reached, then we simply move it to the next minor version milestone. That way, we would be able to point newcomers to the milestone page saying "those are the issues we want to see solved first".