They are there in the edit mode of any profile, except the image examples - which are on the image page (the {{curly braces}} code, anyway).
It gives you instant level 3 header, bold, italic, link to another Wikitree profile (you would need the WT-ID#), and external links. (Also add categories, and surround the citation with <ref>tags</ref>.)
The rest can be easily found by doing as I did -- editing any example profile, or any profile that had a certain "look" I wanted to emulate.
I learnt by trial and error how to add the label parameter to images -- because I did not find the help file that mentioned label until long after I had started using it.
I learnt a lot more by trial and error, by copying what I found in existing profiles - in edit mode - because I did not know about the help files. Now I know the help files exist and all that markup language can be found in those, without the need to edit profiles to see.