Fix PR template link (#94)

Signed-off-by: Kenji Miyake <kenji.miyake@tier4.jp>

.github/PULL_REQUEST_TEMPLATE.md

@@ -24,20 +24,20 @@
 
 ## Pre-Review Checklist for the PR Author
 
-- [ ] Code follows [coding guidelines](coding-guidelines)
+- [ ] Code follows [coding guidelines][coding-guidelines]
 - [ ] Assign PR to reviewer
 
 ## Checklist for the PR Reviewer
 
 - [ ] Commits are properly organized and messages are according to the guideline
-- [ ] Code follows [coding guidelines](coding-guidelines)
+- [ ] Code follows [coding guidelines][coding-guidelines]
 - [ ] (Optional) Unit tests have been written for new behavior
 - [ ] PR title describes the changes
 
 ## Post-review Checklist for the PR Author
 
 - [ ] All open points are addressed and tracked via issues or tickets
-- [ ] Write [release notes](release-notes)
+- [ ] Write [release notes][release-notes]
 - [ ] (When added something to `.repos`) Check if proper access rights are set
 
 [coding-guidelines]: https://tier4.atlassian.net/wiki/spaces/AIP/pages/1194394777/T4