Post migration cleanup

[jamillambert]

There are a couple of things that could be helpful to do now development has migrated to forgejo:

• Close all the open issues that have been migrated across.
  • I believe everything before REPOSITORY MIGRATION MARKER #668 has been successfully migrated so I think all open issues before it can be closed.
  • It might be better to only close the issues that are opened by or being followed up by users that are active on forgejo to still allow non forgejo users to follow up on their issues.
• Add a notification to the readme that the source code here is not the most up to date version now that development has moved off GitHub.

[tcharding]

hmm I was surprised to see all the issues close. That is not to say its not a good idea, just not what I had in mind. Lets do it, we can open them back up later if we want to.

[tcharding]

Lets close em all I mean. No matter who raised them. They can comment on the forge if they want to or raise a new issue if the can't use the forge for some reason.

[tcharding]

Ha! Nice, a comment here: #587 2 hours ago is a good test of our decisions.

[jamillambert]

Notification added to the readme files in #673