[INFRA] Add Github pull request template.#46

**What changes were proposed in this pull request?**
`XSQL` have not created the pull request template. So we must edit the title 'What changes were proposed to this pull request ? ' formatted with bold text when contributor to creating a PR .
This PR add the pull request template, we will easy to create PR after this PR.

.github/PULL_REQUEST_TEMPLATE

@@ -0,0 +1,13 @@
+### What changes were proposed in this pull request?
+<!--
+Please clarify what changes you are proposing. The purpose of this section is to outline the changes and how this PR fixes the issue. 
+If possible, please consider writing useful notes for better and faster reviews in your PR.
+-->
+
+### How was this patch tested?
+<!--
+If tests were added, say they were added here. Please make sure to add some test cases that check the changes thoroughly including negative and positive cases if possible.
+If it was tested in a way different from regular unit tests, please clarify how you tested step by step, ideally copy and paste-able, so that other reviewers can test and check, and descendants can verify in the future.
+If tests were not added, please describe why they were not added and/or why it was difficult to add.
+-->
+