Rewrite CONTRIBUTING.md to be specific to this repo

[Asartea]

Complete the following REQUIRED checkboxes:

• I have thoroughly read and understand The Odin Project Contributing Guide
• The title of this issue follows the brief description of request format, e.g. Add dark mode to website

The following checkbox is OPTIONAL:

• I would like to be assigned this issue to work on it

---

1. Description of the Feature Request:
In #3901 we converted all links to CONTRIBUTING.md in the TOP org to point to the .github version, which is now the source of truth. That leaves the file in this repo now unnecessary in its current state, but it could be useful as a guide in how to contribute to this specific repo, and should be rewritten to fit that purpose

2. Acceptance Criteria:

• Decide upon what should be included, looking also at how the wiki currently fits together
• CONTRIBUTING.md has been rewritten with repo specific information

[CouchofTomato]

Yeah I agree. I don't have time for this at the moment though. See if anyone else wants to take it on.

[CBID2]

I’ll do it @CouchofTomato