use a page for manual pages in no longer supported suites

[pabs3]

For releases that are no longer supported by manpages.d.o (such as squeeze and earlier), I think it would be useful to have a page that points at archive.debian.org and snapshot.debian.org and minimally explains how to find the .deb to download and extract the manual page from the package. The page could also link to the oldest supported suite, and potentially do delayed redirect (using meta refresh) to the oldest supported suite page.

[stapelberg]

Currently, older Debian releases (specifically, I see wheezy, jessie and stretch) are not updated and just left on disk as-is. Notably, if the storage in manziarly.d.o were to break, we likely would not re-generate them.

We don’t want to process older suites to limit resource consumption (RAM in particular) and because it possibly would interfere with cross-referencing/navigation, so the best way to handle older Debian releases is to do a one-off debiman run for them with a custom template, I think.

I don’t have time to get around to this, so if someone wanted to prepare such a template adjustment, do a manual debiman run and verify the results, that’d be a great contribution!