Add PR template (#18)

Author: rocketnova

.github/pull_request_template.md

@@ -0,0 +1,15 @@
+## Ticket
+
+- Resolves #{TICKET NUMBER OR URL}
+
+## Changes
+
+> What was added, updated, or removed in this PR.
+
+## Context for reviewers
+
+> Background context, more in-depth details of the implementation, and anything else you'd like to call out or ask reviewers.
+
+## Testing
+
+> Provide testing instructions and evidence that the code works as expected. Include screenshots, [GIF demos](https://www.cockos.com/licecap/), shell commands or output to help show the changes working as expected. ProTip: you can drag and drop or paste images into this textbox.