Update pull_request_template.md

.github/pull_request_template.md

@@ -1,7 +1,9 @@
-Related issues:
-
-#XXXX
+Related issue: #XXXX
 
 **Description**
 
 A clear and concise description of what the problem was and how this pull request solves it.
+
+<!-- Remove the line below if is not relevant -->
+
+This contribution is funded by [Example](https://example.com).