gh-36602: Tidy PR template

    
<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes #1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->

Our current PR template makes one to think and search for the blank
where to put the description. We tidy the PR template so that it is
obvious where the blank is. Remove other less useful lines.

<!-- Why is this change required? What problem does it solve? -->
<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes #12345". -->
<!-- If your change requires a documentation PR, please link it
appropriately. -->

### 📝 Checklist

<!-- Put an `x` in all the boxes that apply. -->
<!-- If your change requires a documentation PR, please link it
appropriately -->
<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
<!-- Feel free to remove irrelevant items. -->

- [x] The title is concise, informative, and self-explanatory.
- [x] The description explains in detail what this PR is about.
- [ ] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- #12345: short description why this is a dependency
- #34567: ...
-->

<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
    
URL: #36602
Reported by: Kwankyu Lee
Reviewer(s): grhkm21, Kwankyu Lee

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,32 +1,26 @@
-<!-- ^^^^^
-Please provide a concise, informative and self-explanatory title.
-Don't put issue numbers in there, do this in the PR body below.
-For example, instead of "Fixes #1234" use "Introduce new method to calculate 1+1"
--->
-<!-- Describe your changes here in detail -->
+<!-- ^ Please provide a concise and informative title. -->
+<!-- ^ Don't put issue numbers in the title, do this in the PR description below. -->
+<!-- ^ For example, instead of "Fixes #12345" use "Introduce new method to calculate 1 + 2". -->
+<!-- v Describe your changes below in detail. -->
+<!-- v Why is this change required? What problem does it solve? -->
+<!-- v If this PR resolves an open issue, please link to it here. For example, "Fixes #12345". -->
+
 
-<!-- Why is this change required? What problem does it solve? -->
-<!-- If this PR resolves an open issue, please link to it here. For example "Fixes #12345". -->
-<!-- If your change requires a documentation PR, please link it appropriately. -->
 
 ### :memo: Checklist
 
 <!-- Put an `x` in all the boxes that apply. -->
-<!-- If your change requires a documentation PR, please link it appropriately -->
-<!-- If you're unsure about any of these, don't hesitate to ask. We're here to help! -->
-<!-- Feel free to remove irrelevant items. -->
 
-- [ ] The title is concise, informative, and self-explanatory.
+- [ ] The title is concise and informative.
 - [ ] The description explains in detail what this PR is about.
 - [ ] I have linked a relevant issue or discussion.
 - [ ] I have created tests covering the changes.
 - [ ] I have updated the documentation accordingly.
 
 ### :hourglass: Dependencies
 
-<!-- List all open PRs that this PR logically depends on
-- #12345: short description why this is a dependency
-- #34567: ...
--->
+<!-- List all open PRs that this PR logically depends on. For example, -->
+<!-- - #12345: short description why this is a dependency -->
+<!-- - #34567: ... -->
+
 
-<!-- If you're unsure about any of these, don't hesitate to ask. We're here to help! -->