[UX] Make the maintenance mode page more delightful

[stpaultim]

Description of the need

This is a follow-up issue to a PR that went into 1.12.0.

Back in 2019, there was some discussion about doing something creative to the maintenance mode page to improve the user experience and have a little fun with Backdrop. The idea was to lighten the moode and do something creative with the maintenance mode message.

#2528 (comment)

Proposed solution

There were several suggestions.

1. An image or graphic of a dragon with a shovel
2. Displaying some random quotes about Dragons
3. Etc.

Alternatives that have been considered

Being boring...

;-)

[klonos]

If we could get someone in the creative world to perhaps draw Drop lost in cave, holding a lantern in one hand, and its finger from the other hand touching its lip ...similar expression to the famous Mini-Me in Austin Powers (but more like an "uhmm" moment - not the evil-looking kind):