You can help improving and extending this documentation creating a fork and a pull request on GitHub. After review and discussion (if necessary) we will merge your pull request into the documentation repository and then it will be also visible on the site.
Have a look at the README file of the documentation repository for more information. There you will also find a description of how this site is rendered and how inserting a new page into the navigation works.
If you are not willing to contribute directly, you can also write us about your suggestions: firstname.lastname@example.org