Updated to Readme for the formatting of notes.

After reviewing the work Erik was doing on the django formula I realized his readme formatting was fixed for the notes. I've made that change to this perl doc as an example. What do you think about switching up the existing ones like this? Then it ensures the 'note' has a proper box. As a comparison see what the readme looks like here, versus something like Apache: https://github.com/saltstack-formulas/apache-formula.