ATLAS-4983: Add pull request template (#268)

Author: kumaab

.github/pull_request_template.md

@@ -0,0 +1,11 @@
+## What changes were proposed in this pull request?
+
+(Please fill in changes proposed in this fix. Create an issue in ASF JIRA before opening a pull request and
+set the title of the pull request which starts with
+the corresponding JIRA issue number. (e.g. ATLAS-XXXX: Fix a typo in YYY))
+
+
+## How was this patch tested?
+
+(Please explain how this patch was tested. Ex: unit tests, manual tests)
+(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)

pom.xml

@@ -1441,6 +1441,7 @@
                         <exclude>debian/**</exclude>
                         <exclude>.svn/**</exclude>
                         <exclude>.git/**</exclude>
+                        <exclude>.github/pull_request_template.md</exclude>
                         <exclude>.gitignore</exclude>
                         <exclude>**/.idea/**</exclude>
                         <exclude>**/*.twiki</exclude>