Validating PR Issue Checker Workflow (#697)

## Description
 Closes #671 

This workflow ensures that every pull request description includes an
associated issue number for better tracking and clarity. If the required
format is not met, contributors will receive clear feedback on how to
correct it.

## Error Case
**When the PR description does not meet the required format (missing the
issue reference):**

- **PR description:** Fixed bug
- **Output:**
The PR description should include the issue number assigned to you. ⚠️
##[error]An issue reference like 'Fixed #<issue-number>' must be
included in the description.

## Success
- **PR description**: Fixed # or Issue number # or Closes #
- **Output:**
PR description is valid.
All checks passed.





## Checklist
<!-- [X] - put a cross/X inside [] to check the box -->
- [x] I have gone through the [contributing
guide](https://github.com/Anjaliavv51/Retro)
- [x] I have updated my branch and synced it with project `main` branch
before making this PR
- [x] I have performed a self-review of my code
- [x] I have tested the changes thoroughly before submitting this pull
request.
- [x] I have provided relevant issue numbers, screenshots, and videos
after making the changes.
- [x] I have commented my code, particularly in hard-to-understand
areas.


## Additional context:
@Anjaliavv51  please add all the necessary labels

.github/workflows/pr-checker.yml

@@ -0,0 +1,34 @@
+name: PR Issue Checker
+
+on:
+  pull_request:
+    types: [opened, edited]
+
+jobs:
+  check_pr_description:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Check PR Description
+        id: check_pr_description
+        run: |
+          PR_DESCRIPTION="${{ github.event.pull_request.body }}"
+          if [[ -z "$PR_DESCRIPTION" ]]; then
+            echo "PR description is missing."
+            exit 1
+          fi
+
+          # Allow any text before #<issue-number>
+          if [[ ! "$PR_DESCRIPTION" =~ .*\ #[0-9]+ ]]; then
+            echo "The PR description should include the issue number assigned to you.⚠️"
+            echo "##[error]An issue reference like 'Fixed #<issue-number>' must be included in the description."
+            exit 1
+          fi
+
+          echo "PR description is valid."
+
+      - name: Output result
+        run: echo "All checks passed."