Update PULL_REQUEST_TEMPLATE.md context

.github/PULL_REQUEST_TEMPLATE.md

-### Thank you for contributing to Laradock.
+<!--- Thank you for contributing to Laradock -->
 
-##### Make sure you completed the basic 3 steps below:
+##### I completed the 3 steps below:
 
-- [] I've read the simple [Contribution Guide](http://laradock.io/contributing).
+- [] I've read the [Contribution Guide](http://laradock.io/contributing).
 - [] I've updated the **documentation**. (refer to [this](http://laradock.io/contributing/#update-the-documentation-site) for how to do so).
 - [] I enjoyed my time contributing and making developer's life easier :)