Merge pull request #97 from ARMmbed/app-pr-template

Add pull_request_template.md

Author: teetak01

.github/pull_request_template.md

@@ -0,0 +1,23 @@
+<!--
+
+For more information on the requirements for pull requests, please see [the CONTRIBUTING.md](CONTRIBUTING.md).
+
+-->
+
+[] I confirm this contribution is my own and I agree to license it with Apache 2.0.
+[] I confirm the moderators may change the PR before merging it in.
+
+### Summary of changes <!-- Required -->
+
+<!--
+    Please provide the following information:
+
+    Description of the the change (what is this fixing / adding / removing?).
+
+    Why the change is needed, add references to issues if this is a fix.
+
+    Avoid too large commits. Each commit should be an atomic, independent change.
+
+    Write good, descriptive Git commit messages.
+
+-->