Add CONTRIBUTING.md

[naisofly]

Edited to match the current CONTRIBUTING.md template

What is the motivation?

Maintaining the same Contributing Guidelines across all SurrealDB repos

What does this change do?

Updates the current guides to match the agreed-upon template for all SurrealDB repos

Is this related to any issues?

It should give contributors raising a issues a better idea of how we look at contributions from the community. tl;dr: Discord Chat/Github Discussions -> GitHub Issue -> GitHub PR

Have you read the Contributing Guidelines?

• [x] I have read the Contributing Guidelines

[phughk]

Thanks! Merging as build issue is unrelated