Add GitHub Documentation for Developers

[Nougatos]

I found it useful to create some documentation about the documentation 🙂. The main goal is to provide more resources on how to contribute to this great Guide! Feel free to revise any of the rules. I wrote them based on our discussion on your Discord server.

A brief summary of the additions:

• Link in the README.md to CONTRIBUTING.md
• A CONTRIBUTING.md file
• Documentation for setting up local development
• A resources & tools page with tools I personally like to use

You can review all links and documentation on my fork at chore/add-some-developer-documentation.

If any of these additions are inappropriate, I'm happy to adjust them to better align with your vision. 😉

[SandeMC]

GitHub didn't send me a notification for this again, sorry for the delay. Huge thanks for the help!