Update pull_request_template (#366)

## Fixes
<!-- List the issue(s) this PR resolves -->
- The change keeps the checklist clear while making it evident that each
item is optional based on context.

## Checklist
<!-- Put an `x` in the boxes. All tasks must be completed and boxes
checked before merging. -->

- [ ] 🤖 This change is covered by unit tests as required.
- [ ] 🤹 All required manual testing has been performed.
- [ ] 🛡️ Security impacts have been considered.
- [x] 📖 All documentation updates are complete.
- [ ] 🧠 This change does not change third-party dependencies

.github/pull_request_template.md

@@ -1,18 +1,15 @@
 ## Fixes
 <!-- List the issue(s) this PR resolves -->
-
 -
 
 ## Changes
 <!-- List the changes this PR introduces -->
-
 -
 
 ## Checklist
 <!-- Put an `x` in the boxes. All tasks must be completed and boxes checked before merging. -->
-
-- [ ] 🤖 This change is covered by unit tests as required.
-- [ ] 🤹 All required manual testing has been performed.
-- [ ] 🛡️ Security impacts have been considered.
-- [ ] 📖 All documentation updates are complete.
-- [ ] 🧠 This change does not change third-party dependencies
+- [ ] 🤖 This change is covered by unit tests (if applicable).
+- [ ] 🤹 Manual testing has been performed (if necessary).
+- [ ] 🛡️ Security impacts have been considered (if relevant).
+- [ ] 📖 Documentation updates are complete (if required).
+- [ ] 🧠 Documentation updates are complete (if required).