Pages and wikis
You have many options to share content in a collaborative way. In addition to issues and discussions, you can use GitHub Pages and wikis.
GitHub Pages
GitHub Pages is a static website-hosting service that serves your files straight from a repository in GitHub. You could host normal HyperText Markup Language (HTML), Cascading Style Sheets (CSS), and JavaScript files and build a site yourself. But you can also leverage the built-in preprocessor Jekyll (see https://jekyllrb.com/), which allows you to build good-looking websites in Markdown.
GitHub Pages sites are hosted by default under the github.io
domain (such as https://wulfland.github.io/AccelerateDevOps/), but you can also use a custom domain name.
GitHub Pages is a free offering for public repositories. For internal use (private repositories), you need GitHub Enterprise.
Note
GitHub Pages is a free service, but it is not intended for running commercial websites! It is forbidden to run webshops...