chore: PR template comments out new AEP checklist

Often, we are making spot fixes to AEPs, and not introducing
brand new ones. Therefore, the PR template should comment out
new AEP guides rather than requiring it to be removed.

.github/PULL_REQUEST_TEMPLATE.md

@@ -28,9 +28,9 @@ contributing to this repository.
 - [ ] [My code has been formatted](https://aep.dev/contributing#formatting)
       (usually `prettier -w .`)
 
-### Additional checklist for a new AEP
+<!-- uncomment this if this is for a new AEP
 
-<!-- delete if this is not a new AEP -->
+### Additional checklist for a new AEP
 
 - [ ] A new AEP **should** be no more than two pages if printed out.
 - [ ] Ensure that the PR is editable by maintainers.
@@ -40,4 +40,6 @@ contributing to this repository.
       [Document structure](https://aep.dev/style-guide#document-structure)
       guidelines are met.
 
+-->
+
 💝 Thank you!