Add documentation for using Maven repository

[jellysquid3]

We recently deployed a Maven server (https://maven.caffeinemc.net) and started publishing artifacts there, which is necessary to use the mod at all in a developer environment.

There should be a page added to the Wiki which covers where the repository is and how to use it, along with information on which artifacts to use.

Additionally, the README file in the repository should be updated to point to this documentation.

[douira]

I have added a basic page: https://github.com/CaffeineMC/sodium/wiki/CaffeineMC-Maven-&-Config-API