Improve documentation

[Krzmbrzl]

Although I think the system itself is extremely powerful, I also believe that the existing documentation at https://www.boost.org/doc/libs/1_71_0/doc/html/boost_units.html is very poorly written (no offense to the one(s) that wrote it). It certainly covers a lot of stuff and maybe if you already know how things work, it is a great place to look up some (implementation) details.

If on the other hand you don't know the system (yet) and want to get started using it, the documentation is almost completely useless. I might even go a step further stating that it might even be contra-productive to look into the docs for getting started quickly as you'll be more confused than before after doing so (at least that's what i experienced).

Thus I think that there should be a simple Getting Started section that covers, how the library is to be used in general (on this the Quick Start section in the docs is actually not bad) and some simple examples how one can add custom units/dimensions to the system.

The latter might be hidden in the information flood in the following chapters in the docs but they just contain so many "you can do this part like this... or like this... or that way... or completely different altogether" that it is really really hard to extract how things should be done in the end (for a simple example).

Now where am I going with this issue here? I not only want to point out the problem I see (which I could imagine you might be aware of already) but I also want to offer my help at trying to improve the situation.
For this reason I'd like to know where and how I can submit patches to the documentation of this boost library.