Expand and clean up documentation

[haugene]

The documentation contains a lot of good stuff, but it's not well structured and there are a lot of blank spots.
To reduce the amount of repeated questions here in the issues we should do a re-write and try to cover all the top asked questions in a FAQ.

At the time of writing this I have already started but I won't be "done" very soon. I want to push what I have anyways because I think it's better than what is there now. Also it puts a bit of pressure on myself to get the rest done. I'll drop a few links to this issue in them as well so that others might want to elaborate where I've fallen short.

[ajhorvath20]

Great work @haugene and much appreciated

[clement-z]

Hi @haugene, do you have a checklist/todolist for the rewrite ? If not maybe you can consider adding it as a comment on this issue ?

Although short on time currently, I'm down to help where I can.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.

[stale[bot]]

Feel free to re-open this issue if you think it deserves another look.

[haugene]

I have to continue here later. But it's not done. So I'm opening it again. If nothing else, dear stalebot will remind me in a couple of month.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.

[Lexicanium]

any updates? Need to read this documentation, what is the most recent version to read?..

[pkishino]

there is only one documentation linked from the readme..