Update welcome message for first-time contributors

.github/workflows/first-time-contributor.yaml

@@ -10,7 +10,6 @@ permissions:
 jobs:
   welcome:
     runs-on: ubuntu-latest
-
     steps:
       - name: Welcome first-time contributor
         uses: actions/github-script@v7
@@ -36,54 +35,54 @@ jobs:
               return;
             }
 
+            // Construct the welcome message
             const body = `👋 Hi @${prAuthor}, welcome to **PipeCD** and thanks for opening your first pull request!
-
-We’re really happy to have you here 🚀  
-Before your PR gets merged, please check a few important things below.
-
----
-
-### Helpful resources
-- Contributing guide: https://github.com/pipe-cd/pipecd/blob/master/CONTRIBUTING.md
-- Development setup: https://github.com/pipe-cd/pipecd/blob/master/CONTRIBUTING.md#development
-
----
-
-### DCO Sign-off
-All commits must include a \`Signed-off-by\` line to comply with the Developer Certificate of Origin (DCO).
-
-In case you forget to sign-off your commit(s), follow these steps:
-
-For the last commit:
-\`\`\`bash
-git commit --amend --signoff
-git push --force-with-lease
-\`\`\`
-
-For multiple commits:
-\`\`\`bash
-git rebase --signoff origin/master
-git push --force-with-lease
-\`\`\`
-
----
-
-### Run checks locally
-Before pushing updates, please run:
-\`\`\`bash
-make check
-\`\`\`
-This runs the same checks as CI and helps catch issues early.
-
----
-
-### 💬 Need help?
-If anything is unclear, feel free to ask in this PR or join us on the CNCF Slack in the **#pipecd** channel.
-You can get your Slack invite from: https://communityinviter.com/apps/cloud-native/cncf
-
-
-Thanks for contributing to PipeCD! ❤️
-`;
+
+            We’re really happy to have you here 🚀
+
+            Before your PR gets merged, please check a few important things below.
+
+            ---
+
+            ### Helpful resources
+            - Contributing guide: https://github.com/pipe-cd/pipecd/blob/master/CONTRIBUTING.md
+            - Development setup: https://github.com/pipe-cd/pipecd/blob/master/CONTRIBUTING.md#development
+
+            ---
+
+            ### DCO Sign-off
+            All commits must include a \`Signed-off-by\` line to comply with the Developer Certificate of Origin (DCO).
+
+            If you forgot, you can fix it like this:
+
+            **For the last commit:**
+            \`\`\`bash
+            git commit --amend --signoff
+            git push --force-with-lease
+            \`\`\`
+
+            **For multiple commits:**
+            \`\`\`bash
+            git rebase --signoff origin/master
+            git push --force-with-lease
+            \`\`\`
+
+            ---
+
+            ### Run checks locally
+            Before pushing updates, please run:
+            \`\`\`bash
+            make check
+            \`\`\`
+            This runs the same checks as CI and helps catch issues early.
+
+            ---
+
+            ### 💬 Need help?
+            If anything is unclear, feel free to ask in this PR or join us on the CNCF Slack in the **#pipecd** channel.
+            You can get your Slack invite from: https://communityinviter.com/apps/cloud-native/cncf
+
+            Thanks for contributing to PipeCD! ❤️`;
 
             await github.rest.issues.createComment({
               owner,