update pull request template

Author: Chris Cho

.github/pull_request_template.md

@@ -1,16 +1,17 @@
 ## Pull Request Info
 
 ### Issue JIRA link:
-https://jira.mongodb.org/browse/DOCSP-NNNN
+https://jira.mongodb.org/browse/DOCSP-NNNNN
 
 ### Docs staging link (requires sign-in on MongoDB Corp SSO):
 https://docs-mongodborg-staging.corp.mongodb.com/NNNNNNN/java/docsworker-xlarge/NNNNNNNNNNN/
 
 ### Self-Review Checklist
 
-- [ ] Are there any warnings or errors in the RST?
+- [ ] Is this free of any warnings or errors in the RST?
 - [ ] Did you run a spell-check?
 - [ ] Did you run a grammar-check?
 - [ ] Does it render on staging correctly?
+- [ ] Are all the links working?
 - [ ] Are the staging links in the PR description updated?