Fix compile error, add assets and unified readme

[guillaume-haerinck]

First take on an unified readme format used accross every O3DE samples (and checked that the project still runs correctly on the release of 23.10.3)

The goal being to make the samples more accessible to the users. Both by updating the project's readme, adding a version check and linking them in O3DE showcase and doc pages. Task tracked via this issue : o3de/o3de.org#2549

As kenney's assets are CC0 license, I think its best to include them directly in the repository to reduce the number of steps to be done to run the game. The same logic was applied concerning O3Tanks. I can still mention it in the readme if you prefer it this way.

I believe it is one of the best O3DE usage out there, you C++ scripting is well done and it should be a good guide for O3DE newcommers. Adding it in the "official" samples list and later on in the O3DE launcher would greatly improve the accesibility of the engine

[guillaume-haerinck]

Changes visible here : https://github.com/guillaume-haerinck/games.o3de.o3de-jam-2305/tree/unified_readme