Documentation is missing and should be expanded

[oryband]

Basically what the title says. Also, more examples should be added.

See the other issues I've opened for examples on what I mean: #82 #83

[rcrowley]

I obviously agree but don't have time. Hopefully http://godoc.org/github.com/rcrowley/go-tigertonic helps out a bit, too.

[oryband]

@rcrowley Eventually reading the whole source made me reach the solution on my own, but took a long unnecessary time.