Update PULL_REQUEST_TEMPLATE to include an API spec change in the che…

…cklist. (opensearch-project#679)

Signed-off-by: dblock <[email protected]>

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,22 +1,16 @@
-**Is your feature request related to a problem? Please provide an existing Issue # , or describe.**
-A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+### Description
+[Describe what this change achieves]
 
-**Describe the solution you are proposing**
-A clear and concise description of what you want to happen.
-
-**Describe alternatives you've considered**
-A clear and concise description of any alternative solutions or features you've considered.
-
-**Additional context**
-Add any other context or screenshots about the feature request here.
+### Related Issues
+Resolves #[Issue number to be closed when this PR is merged]
+<!-- List any other related issues here -->
 
 ### Check List
-- [ ] Backport Labels added.
 - [ ] New functionality includes testing.
-  - [ ] All tests pass
 - [ ] New functionality has been documented.
-  - [ ] New functionality has javadoc added
-- [ ] Commits are signed per the DCO using --signoff
+- [ ] API changes companion pull request [created](https://github.com/opensearch-project/opensearch-api-specification/blob/main/DEVELOPER_GUIDE.md).
+- [ ] Commits are signed per the DCO using `--signoff`.
+- [ ] Public documentation issue/PR [created](https://github.com/opensearch-project/documentation-website/issues/new/choose).
 
 By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
 For more information on following Developer Certificate of Origin and signing off your commits, please check [here](https://github.com/opensearch-project/performance-analyzer/blob/main/CONTRIBUTING.md#developer-certificate-of-origin).