Fix spelling

non-network-reachable not non-network-reachble

What can I say, I'm a Virgo.
Added a .gitignore.
Removed all of the old README since I'm going to refactor and reorganize it.
Added in a table of contents and basic structure that matches the Puppet Labs Postgres module's README.
Added id: anchor links to the section headers.
Added in the Overview section text from the old README.
Added a piece to the Setup section text from the old README.
Added the old server requirements text from the old README to the Setup section.
Added the server usage section from the old README.
Added the NRPE usage section from the old README.
Added the first chunk of the Icinga 2 object usage section.
Wording.
Added an Objects usage section.
Added table of contents entries and anchor links for the ojbect sections in the README.
Added an apply_service_to_host chunk to the object usage section.
Added the actual apply_service_to_host chunk.
Added a hostgroup placeholder chunk to the object usage section.
Added an idomysqlconnection chunk to the object usage section.
Added an idopgsqlconnection chunk to the object usage section.
Added an anchor link to the idopgsqlconnection usage section header.