The changelog isn't really meant as a help file, but just a list of changed/fixed/new items and sometimes a short description. So it doesn't really need to be any more clear. The help file could definitely use some improvements in certain areas, and you can find various posts recommending improvements. In general, it is a very useful file and is quite useable as-is, so it's most likely low on the priority list of things to work on. There are a variety of undocumented commands/etc, but there are also various online resources that list these commands and what they do, so if you wanted to look at the commands, it's easy enough to do so. The one problem with using undocumented commands is that they may be removed at any time, where documented commands aren't going anywhere.