README.so is a simple online editor that helps developers quickly create and customize professional README files for their projects using a user-friendly interface.

If you maintain an open-source project in the range of 10k-200k lines of code, add an ARCHITECTURE document next to README and CONTRIBUTING. Keep it short: every recurring contributor will have to read it. Only specify things that are unlikely to frequently change. Don’t try to keep it synchronized with code. Instead, revisit it a couple of times a year.