What is it?
Markdown is a lightweight markup language with plain text formatting syntax. It's relatively easy to learn and use, and displays well on GitHub; versions of it are also used in Slack, Trello and Jira, among others. This documentation is written using it. It's worth learning, if you haven't already.
There's a great tutorial on the Commonmark website.
- GitHub markdown cheatsheet
- Trello markdown cheatsheet
- Jira markdown cheatsheet
- Slack markdown cheatsheet
The CivicActions guidebook is written in markdown. You can find more information about that on this guidebook Markdown page.