Create pull request template.

Author: briensea

.github/workflows/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,7 @@
+_Issue #, if available:_
+
+_Description of changes:_
+
+_Target (OCI, Managed Runtime, both):_
+
+By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.