Warn users about retirement on 22 September

[bjgill]

https://trello.com/c/OS5OSEVl/144-1-decide-whether-to-migrate-shared-repos-to-ccs

We recently discovered that the Digital Marketplace team was responsible for this repo. We don't have the time or expertise to fix the accessibility issues, and we're moving to CCS soon. We asked, and no other team in GDS/CDIO wanted to take it on. So we're going to retire it in an orderly fashion.

3 weeks is probably long enough for people to notice. They'll be able to find something else, or let us know if they want to take it on to stop the retirement. Otherwise, we'll switch it off after that date.

Thanks to @abersager who created this, @lfdebrux who's been maintaining it for the past year, and everyone else that contributed to a tool that was useful to many.

[bjgill]

For reference, the Slack thread: https://gds.slack.com/archives/CACV4GHCL/p1630060841018600

@lfdebrux, who's done all the maintenance in the past year, indicated he thought it should be retired. My plan is to leave it archived in alphagov in case anyone wants to resurrect it in future.

[bjgill]

Going to hold off for the moment - CCS might want to take this over instead

[bjgill]

OK. CCS have decided not to adopt this. let's continue with the retirement. 2 weeks is a bit tight, but should be long enough.