Creates a PR template

@priley86 @dlabrecq I've created this PR template to help get better PR descriptions and improve our for release notes.

What do you think?

Author: andresgalante

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,18 @@
+## Description
+A few sentences describing the overall goals of the pull request's commits.
+
+Include related PRs or Issues
+
+Include a list of changes:
+
+* Change 01
+* Change 02
+* Change 03
+
+## Link to rawgit and/or image
+
+For example: Here is a [Link to Alerts](https://rawgit.com/patternfly/patternfly/master-dist/dist/tests/alerts.html)
+
+This is an image:
+
+![Image of Yaktocat](https://octodex.github.com/images/yaktocat.png)