Write README

[jackjennings]

Add:

• Sample controller (where to use it)
• Explanation of the form duck type
• Installation instructions
• TravisCI badge
• Rubygems badge
• Logo

Anything else?

That seems like a good start! What else...a Travis CI badge and a logo (TBD)?

[jackjennings]

I just added the badge 😉

[jackjennings]

(Updated with both of those)

[jackjennings]

Rubygems badge:

[![Gem Version](https://badge.fury.io/rb/microform.svg)](https://badge.fury.io/rb/microform)