Editorial work on first paragraph of data request letter
Remove discussion of sharing data more broadly from data request

This sounds to much like us wanting to give other peoples data
away (whatever that means) for a first email contact. The most
important thing here is to not scare people off. We can offer to
help them make things available down the line after getting off
the ground.
Add mention of citing, acknowledgement, and other restrictions
Merge pull request #13 from ethanwhite/letter-edits

Hilarious. Was in the middle of an identical set of edits.