I designed two tools to help maintainers grow their open source communities: the community profile checklist and code of conduct template picker. Here are some snippets from the GitHub blog post:
As an open source project grows beyond code, it can be difficult to maintain new contributions, documentation, issues, and the legal side of running a larger project. On your community profile, you’ll see a checklist showing how your project compares to our recommended community standards. From there, you can easily add any missing files.
As your project grows and matures, it’s often necessary to spell out community roles, norms, and expectations. One of the recommended best practices is to add a code of conduct to your project. If you click the prompt from your community profile (or begin adding a CODE_OF_CONDUCT.md file to your repository), you’ll see a short list of common templates to choose from. Then you can create a pull request to add a code of conduct to your repository.