Add GitHub PR template

Author: colemancda

.github/pull_request_template.md

@@ -0,0 +1,15 @@
+**Issue**
+
+Fixes #1.
+
+**What does this PR Do?**
+
+Description of the changes in this pull request.
+
+**Where should the reviewer start?**
+
+`main.swift`
+
+**Sweet giphy showing how you feel about this PR**
+
+![Giphy](https://media.giphy.com/media/rkDXJA9GoWR2/giphy.gif)