ci: add config tester overlay for Gitlab Pages and restructure scripts
This MR adds the behaviour of Pages deployment. The new procuedure looks like this:
In the /public directory we now only keep
[current branch] directories. Each of them additionally creates a
config-tester directory inside. There we provide a separate HTML file for each project configuration. So now we have
gfl.html in there. On the website you can see a menu on top right to switch between those HTML files.
So each needed environment has also its own Config Tester.
The URL looks like this: https://subugoe.pages.gwdg.de/emo/tido/main/config-tester/ahiqar.html