My colleague and I have been dipping our toes in the world of maintaining and porting Backdrop CMS contrib modules and are running into some questions.
What is the best practice or recommendation for writing and sharing documentation for Backdrop contrib modules?
Since we use GitHub, it would be best to adopt whatever best practice exists for documenting on GitHub. The contents of the README file on the GH repo becomes the summary available on BackdropCMS.org. For a simple project that may be enough. For more complex documentation requirements, use the GH project wiki. Project releases on GH automatically get a project listing on BackdropCMS.org, and links are also automatically created there to the project page, issue queue and wiki.