Document fundamental project setup and code architecture

[mtemnov]

Create a document where the following is documented:

• How will we deal with multiple game variants and how should the implementation look like from a code architecture point of view?
• How is the currently implemented training script working?
• How to start the API and frontend?

[mtemnov]

Results stored at: https://docs.google.com/presentation/d/1JS8UjklKJxhE6ng7H0WRhPnvbJv3N4M0/edit?usp=share_link&ouid=108221830328545531789&rtpof=true&sd=true