Update request letter wording

- Included e-mail address, as requests often get forwarded around and copied and pasted and headers get lost
- 'Custodian of Records' is FOIA nomenclature, and 'Responsible Authority' is the MGDPA term
- Changed statute references to standard legal citation
- Added optional researcher note, which earns additional accessibility under law
- Changed references to Minnesota Government Data Practices Act. It's used both ways, but the actual law is called that and most legislative briefings and policies reference the full name.
- Added statutory reference to downloading using own equipment being permitted.
- Fixed typo.
- Specifically stated that no fees are authorized up-front, as there have been incidents where staff has started making paper copies and demanded fees.
Merge pull request #1 from webster/master

Updated data inventory request language