Updated content to conform to README best practices template

Before alterations, this content was the module author- determined
description of and instructions for use of the module.

As part of a joint Forge/Docs team effort to standardize formatting and
encourage quality module documentation, a best practices README
template was created via internal and external user testing. That
template was then applied to this module.

I pulled in content from the original README on GitHub and in-code
comments. Standard headings were added (Overview, Module Description,
Setup, Usage, etc.) to organize content, existent content was moved
under its appropriate heading and edited for tone/flow/clarity, and
basic formatting was done to adhere to template standards.
I chose to leave off a Reference section as all bits of the inner
workings of the module are called out and discussed under Usage.
Updated init.pp documentation

This class is largely empty BUT serves a purpose, as @jeffmccune
explained to me. Updated the documentation in the header to reflect
this information.
Remove incorrect information, update phrasing, insert backslashes, and fix typos/capitalization errors

This update fixes capitalization and typographical errors, removes
incorrect information (the inclusion of "services" specifically),
updates the phrasing, and inserts backslashes where they were missing.
Merge pull request #21 from laurenrother/README-update

Readme update