Update release-issue-template.md with javadoc reminder

.github/ISSUE_TEMPLATE/release-issue-template.md

@@ -21,6 +21,7 @@ assignees: ''
 - [ ] If any Jakarta or MicroProfile API docs are updated with this release, work with development to get the updates merged to the `docs-javadoc` repo (1-2 weeks before GA)
 - [ ] All issues with a label for this release and any other issues included in the release milestone are completed and closed, with content merged to vNext. (~3 working days before GA)
 - [ ] All autogenerated documentation is refreshed on draft (~3 working days before GA)
+- [ ] Liberty API/SPI documentation is [updated in the docs-javadoc repo](https://github.com/OpenLiberty/docs-javadoc#preparing-open-liberty-api-and-spi-javadoc-files-for-publication) and verified on staging site. (3 working days before GA)
 - [ ] Confirm with the team that docs are frozen and no more updates will be sent to vNext (3 working days before GA).
 - [ ] Verify main feature epic statuses to ensure that all targeted features will be included in the release (before closing doc feature issues and again 1-2 working days before GA).
 - [ ] [Publish docs to production on GA](https://github.com/OpenLiberty/docs-playbook#publishing-a-new-release-of-open-liberty-docs)