chore: Update PULL_REQUEST_TEMPLATE.md (#23270)

* chore: Update PULL_REQUEST_TEMPLATE.md

This is part of an initiative to disseminate PR-specific information for all PR stakeholders. In addition to reviewers, this information is needed by product and docs.

* chore: Update PULL_REQUEST_TEMPLATE.md

* chore: Apply suggestions from code review

Co-authored-by: Sam Arnold <sarnold@influxdata.com>

Co-authored-by: Jeffrey Smith II <jsmith@influxdata.com>
Co-authored-by: Sam Arnold <sarnold@influxdata.com>

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,14 +1,30 @@
-Closes #
-
-Describe your proposed changes here.
-
-<!-- Please DO NOT update the CHANGELOG, as this is now handled by automation. -->
-<!-- Checkboxes below this note can be erased if not applicable to your Pull Request. -->
-
-- [ ] [Well-formatted commit messages](https://www.conventionalcommits.org/en/v1.0.0/)
-- [ ] Rebased/mergeable
-- [ ] Tests pass
-- [ ] http/swagger.yml updated (if modified Go structs or API)
-- [ ] Feature flagged (if modified API)
-- [ ] Documentation updated or issue created (provide link to issue/pr)
+- Closes #
+### Required checklist
+- [ ] Sample config files updated (both `/etc` folder and `NewDemoConfig` methods) (influxdb and plutonium)
+- [ ] openapi swagger.yml updated (if modified API) - link openapi PR
 - [ ] Signed [CLA](https://influxdata.com/community/cla/) (if not already signed)
+
+### Description
+1-3 sentences describing the PR (or link to well written issue)
+
+### Context
+Why was this added? What value does it add? What are risks/best practices?
+
+### Affected areas (delete section if not relevant):
+List of user-visible changes. As a user, what would I need to see in docs?
+Examples:
+CLI commands, subcommands, and flags
+API changes
+Configuration (sample config blocks)
+
+### Severity (delete section if not relevant)
+ i.e., ("recommend to upgrade immediately", "upgrade at your leisure", etc.)
+
+### Note for reviewers:
+Check the semantic commit type:
+ - Feat: a feature with user-visible changes
+ - Fix: a bug fix that we might tell a user “upgrade to get this fix for your issue”
+ - Chore: version bumps, internal doc (e.g. README) changes, code comment updates, code formatting fixes… must not be user facing (except dependency version changes)
+ - Build: build script changes, CI config changes, build tool updates
+ - Refactor: non-user-visible refactoring
+ - Check the PR title: we should be able to put this as a one-liner in the release notes