Update pull request template

- [ci docs] doesn't work.
  We require CI to pass for non-admins to merge, so `[ci docs]` is
  more harmful. Also GitHub actions are reasonably fast,
  so overall it's ok to let it make builds

- Mention `changelog.d` directory

.github/PULL_REQUEST_TEMPLATE.md

@@ -3,8 +3,7 @@
 Please include the following checklist in your PR:
 
 * [ ] Patches conform to the [coding conventions](https://github.com/haskell/cabal/blob/master/CONTRIBUTING.md#conventions).
-* [ ] Any changes that could be relevant to users have been recorded in the changelog.
+* [ ] Any changes that could be relevant to users have been recorded in the changelog (add file to `changelog.d` directory).
 * [ ] The documentation has been updated, if necessary.
-* [ ] If the change is docs-only, `[ci skip]` is used to avoid triggering the build bots.
 
 Please also shortly describe how you tested your change. Bonus points for added tests!