Update the cookbook readme to reflect the current cookbook

Remove a few sections that weren't valid, reaorder the attributes, fix
wording, capitalize many many things, stop referring to Nagios client
when it should be NRPE.
Further cleanup of the formatting to better display on Github
Merge pull request #92 from tas50/COOK-2216

Cook 2216: Readme cleanup to remove invalid content and reformat for better display