User guide for crunch-lambda

[David Whiting]

With the 0.14.0 release happening, I'd like to write a user guide on the
new crunch-lambda module. What is the best way to do this? Does it belong
on the crunch.apache.org page, and if so, how do I go about contributing to
it? I'll probably write it up on my blog either way, but would be good to
include something in the official docs as well I think.