chore: add PR template (#633)

Relates to #621

Author: Splaktar

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,19 @@
+<!-- 
+Filling out this template is required. Do not delete the template when submitting a Pull Request.
+-->
+## PR Checklist
+<!-- Please check verify and then check each option using "x". i.e. "- [x] The..." -->
+Please check that your PR fulfills the following requirements:
+- [ ] The commit message follows [our guidelines](https://github.com/angular/components/blob/master/CONTRIBUTING.md#commit)
+- [ ] Tests for the changes have been added or weren't appropriate
+
+## What is the current behavior?
+
+
+Issue Number: 
+
+
+## What is the new behavior?
+
+
+## Other information