Cognesia

This is basically the first cut of the engine, implements the game cognesia,

after this tag cognesia won't work anymore and content not needed for engine development will be removed as needed. In other words a more formal proper production of the engine starts immediately following this tag.

This last commit is done on zig version:

0.11.0-dev.1370+d87a58dfa

the game is available on https://peterino2.itch.io/cognesia