Add play_2048
This is yet another implementation of the 2048 game featuring theme switching, three board sizes, state saving and fullscreen mode.

Ingredients were compiled on a too new system and hence cannot run on all stil-supported Ubuntu LTS releases.
What does "still-supported Ubuntu LTS release" mean? According to https://ubuntu.com/about/release-cycle there are these concepts:
Hardware and maintenance updates Interim release Standard Support Extended Security Maintenance (ESM)
Currently, the program cannot be compiled in Ubuntu 18 because it provides csfml 2.4 and this requires csfml 2.5.
I've added an AppImage build under Ubuntu 18.04. Please, consider again the pull request.
(Note: I don't understand the reason of the check failure)
Superseded by #2994