PR template has typos and disagrees with CONTRIBUTING.md

Problem:  The PR template has typos, calls the "related:" header
          "references:", and does not agree with CONTRIBUTING.md on
          Signed-off-by or with AGENTS.md on the Solution line.
Solution: Fix the typos and make the template agree with them.

closes: #21397

Assisted-by: Claude
Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

.github/pull_request_template.md

@@ -8,9 +8,9 @@ are not shown in the pull request; delete any section that does not apply.
 ### What does this change do?
 
 <!--
-One or two sentences, please clearly write what problem this PR fixes,
-for visual changes, a before/after screenshot is helpful
- -->
+In one or two sentences, please clearly write what problem this PR fixes.
+For visual changes, a before/after screenshot is helpful.
+-->
 
 ### Commit message
 
@@ -18,7 +18,7 @@ for visual changes, a before/after screenshot is helpful
 Changes to the C core are merged with a message in this form.
 
     Problem:  <one short sentence: what is wrong, from the user's point of view>
-    Solution: <one short sentence: what this does about it>
+    Solution: <one short sentence: what this does about it> (Your Name).
 
 Anything longer (mechanism, benchmark numbers, why an alternative was
 rejected) goes in the body below the Solution line.
@@ -34,12 +34,12 @@ filetype: for changes to filetype detection
 -->
 
     Problem:  Problem line
-    Solution: Solution line
+    Solution: Solution line (Your Name).
 
 <!--
-If this PR references a previously merged one, add a references: #number
+If this PR references a previously merged one, add a related: #number
 If this PR fixes a reported issue, add a fixes: #number
-Keep the closes: header, it will be filled out when merging the PR
+Keep the closes: header; it is filled in when the PR is merged
 
 Align the # columns
 -->
@@ -59,13 +59,13 @@ Please disclose AI involvement by adding the trailer
 ### Checklist
 
 - [ ] The commit message follows the Problem/Solution form above
-- [ ] `Signed-off-by:` trailer is present (`git commit -s`)
+- [ ] `Signed-off-by:` trailer is present (`git commit -s`), recommended but not required
 - [ ] Tests were added, existing tests cover the change, or the change cannot be tested (say why)
-- [ ] Documentation under `runtime/doc/` was updated
+- [ ] Documentation under `runtime/doc/` was updated, or no update is needed
 
 ### Anything reviewers should know
 
 <!--
-For example: a behaviour change users may notice, a platform you could
+For example: a behavior change users may notice, a platform you could
 not test on, or an assumption the change relies on.
 -->