Hi Andreas, and welcome to TikiWiki Community!
Thanks for your message, you are very right, it was not available by our mistake (there are many things to improve here and there...). Fixed (viewable by registered, right now: try again)
You are very welcome to help us improve the tw.o sites, as soon as you learn how to do things! and Documentation is a very valuable place which needs lots of care to keep it updated and user friendly, etc.