Recommend using GitHub's Codespaces for the development of/contributions to CRA

Created by: darcyclarke

Is your proposal related to a problem?

Currently checking out & running create-react-app's tests makes some changes to your development machine if you're not running in a Docker container/sandboxed environment; this can be frustrating for new, potential contributors.

Describe the solution you'd like

I'm proposing that we use/recommend GitHub's Codespaces for new contributions, especially if they are small in nature. This recommendation should help increase the number of folks that participate in the project as it should reduce the friction to contribution.

Describe alternatives you've considered

• Refactoring the project/tests to not modify environment configs &/or ensure it cleans up after itself

Additional context

• We previously discussed this change/recommendation in a maintainers call

/cc @iansu @mrmckeb