Mention abandoned packages in their documentation

[ElectricMaxxx]

I do not whant to remove their docs as the docs are correct until we stopped maintaining, but we should add a kind of a hint to mark the abandoned. And we should explain what that means:

• older versions still work until we stoped maintaining
• except bug no one is able to care atm
• "you would like to maintain?"

[dbu]

i would use the term "currently unmaintained" instead of abandoned, to make our intention clear.

[ElectricMaxxx]

Easier for me to write and speak too.