Add a wiki for documentation

[mcoles]

There's already the ability to create wiki pages, we just need to actually create them:

https://github.com/tableau/community-tableau-server-insights/wiki

[danhislop]

I'd be interested in helping with this wiki - what are you envisioning beyond the README? I found the .twb files helpful but could improve the README in a few places. I also could imagine framing a little more context around the whole procedure (sort of before and after the README's timeline).

[mcoles]

Hey Dan, thanks! Any help you can provide would be very much appreciated. It's been a while since I opened this issue, but I think at the time that my thought process was that there's a lot of information that people could benefit from that doesn't fit within the workbooks or the field comments because it's too detailed. I see people ask a lot of questions of the nature "how do I do X?", so it might be useful to post some answers to them--or in the case that these data sources can't do what they need, to state as much. I would guess, though, that anything you would personally find helpful would also be helpful to others.