4.x: Add pull request template (helidon-io#7342)

* Add pull request template
* Update

Author: barchetta

.github/pull_request_template.md

@@ -0,0 +1,10 @@
+
+### Description
+
+### Documentation
+
+If enhancement: provide description with example code/config snippet or pointer to issue with the description
+
+If feature: summarize feature and provide pointer to doc issue
+
+If no doc impact: None