add a main page for the group (whole project)

Description

During our (@abcdev) workshop with @FrankNagel and @cmarschl, we realized together that it would be nice to have a main (starting page) of the group (project), as https://openstapps.gitlab.io returns 404.

Explanation

It is good to have one place which is starting point into the project's documentation. We need a repository which will be responsible for serving the group page(s). I was thinking of using this repository (@openstapps/projectmanagement) but for me it's not good idea, because @openstapps/projectmanagement is already a tool (a npm package), and we need a separate documentation for it too, as for other packages.

The page would have links to project docs as well as to other projects (their docs) of the group (@krlwlfrt GitLab API could probably help with the list?) and list of licence plates.

We could eventually (with the help of @openstapps/projectmanagement) generate reports for StApps meetings and add link to the list of them to this start page.

Dependencies, issues to be resolved beforehand

No.

How to

https://www.youtube.com/watch?v=TWqh9MtT4Bg

Please comment @All