[proposal] create a minimal CONTRIBUTING.md

[ghost]

As a new contributor I would like to understand and respect the maintenance standards for this repository.
I propose we create a CONTRIBUTING.md to briefly document what to expect contributing to this repository.

I and @coriolinus are strapped for time so I am on the fence about doing this. I am on the fence because I do not want to drain from our primary goal of high-quality concept exercises for the v3 launch.

So, the first step would be to decide whether we add one.
Then, let's define simple content.

I would appreciate even if this was something like:

The current active maintainers are [insert our handles or link to the code]
Their time is limited and so a proper introduction to maintaining the Rust track is out of scope!
But we would appreciate contributions using these basic guidelines.

As an aside, I feel like contributing concept/ entries is quite well-defined and self-contained. So it may lend to us documenting clearly how to do it. But it is technical writing. Writing about Rust versus writing Rust. In fact, I would argue most of the v3 concept exercise development has been this kind of meta. Encoding teaching Rust in Exercism's format!

[coriolinus]

IMO this is a good idea, but fairly low priority. If we do it, it should be more thorough than the 3-line suggestion. I don't think we should complain about limited time there.

[ghost]

Topics I would like to cover:

for maintainers

• should I force push to my branches during a PR review?
• branches policy in the repository
• how we use issues and labels
  • Deferring to the outcome of standardize a core maintenance label taxonomy  docs#27
• merging philosophy and process
  • if a reviewer provides a GH suggestion, is our etiquette to always accept that to ensure attribution in the git history?
• how to create a new concept exercise
  • I am finding creating a draft PR with only exemplar a great strategy. I'll plan on drafting a simple how to guide at some point.

for one-time, occasional, or other contributors

• what can I help with? In 5 minutes? in 50 minutes? In 6 hours?

[ghost]

Exercism's community process for contributing and maintaining lives here.

[ghost]

#1177 introduced basic contributing guidelines.

#1156 introduced notes for maintainers.

There are other ideas I had here that may be nice to do, but I will close this issue since the core topic has been addressed.