Use psake/.github files (#68)

## Description
This PR will remove the individual files from the `.github` and allow
the org level files to show up.

## Motivation and Context
This allows a more consistent experience across the different
repositories.

## How Has This Been Tested?
Testing not necessary.

---------

Signed-off-by: Gilbert Sanchez <me@gilbertsanchez.com>

Author: HeyItsGilbert

.github/CONTRIBUTING.md

@@ -4,7 +4,7 @@
     }
     BuildHelpers     = '2.0.16'
     Pester           = @{
-        MinimumVersion = '5.2.2'
+        MinimumVersion = '5.6.1'
         Parameters = @{
             SkipPublisherCheck = $true
         }