Make a "getting involved" wiki page

[camio]

It would be nice if we have a very beginner-friendly page for getting involved with the reactive community. This change may entice some to join the community who otherwise wouldn't. This sort of relates to #7 and would certainly mention #17 if implemented.

It could walk through questions like:

• What's too beginnerish of a question to ask on the mailing list (none hopefully!).
• I found a bug, how do I report it?
• What are some fun things to do immediately? (Tutorial/play tetris)
• Which packages do I need to get up and running?
• Who's the big commercial sponsor of reactive? Anygma!
• . . .