This site is a wiki. It's composed of articles that anybody can edit. You can see a list of the articles here. Articles can be viewed rendered (by default) or as the raw text of the article using the link on the article page.
You can create new articles by going to an article that does not exist from the main page or by creating the url such as "/articles/my_test_article". If you navigate to an article that does not exist, you will be prompted to create it if you want to. Titles may only consist of alphanumeric characters and underscores.
You can add to (or remove from) articles content by editing them. Each article page has a link at the bottom to edit, which will bring up a text box in the browser. When you update the text, the article will changed to reflect the new text. Articles can be formatted with markdown
Each article page has a list to a link of it's previous versions. Versions are unix epoch timestamps in nanoseconds, and are displayed newest to oldest.