add short titles to frontmatter (#20131)

content/github/authenticating-to-github/troubleshooting-commit-signature-verification/checking-your-commit-and-tag-signature-verification-status.md

@@ -12,6 +12,7 @@ versions:
 topics:
   - Identity
   - Access management
+shortTitle: Check verification status
 ---
 ## Checking your commit signature verification status
 

content/github/authenticating-to-github/troubleshooting-commit-signature-verification/index.md

@@ -15,5 +15,6 @@ children:
   - /checking-your-commit-and-tag-signature-verification-status
   - /updating-an-expired-gpg-key
   - /using-a-verified-email-address-in-your-gpg-key
+shortTitle: Troubleshoot verification
 ---
 

content/github/authenticating-to-github/troubleshooting-commit-signature-verification/updating-an-expired-gpg-key.md

@@ -11,6 +11,7 @@ versions:
 topics:
   - Identity
   - Access management
+shortTitle: Update expired GPG key
 ---
 If your key is expired, you must [update the expiration](https://www.gnupg.org/gph/en/manual/c235.html#AEN328), export the new key, delete the expired key in your GitHub account, and [upload the new key to GitHub](/articles/adding-a-new-gpg-key-to-your-github-account/). Your previous commits and tags will show as verified, as long as the key meets all other verification requirements.
 

content/github/authenticating-to-github/troubleshooting-commit-signature-verification/using-a-verified-email-address-in-your-gpg-key.md

@@ -11,6 +11,7 @@ versions:
 topics:
   - Identity
   - Access management
+shortTitle: Use verified email in GPG key
 ---
 {% ifversion fpt %}
 If you need to verify your GitHub email address, see "[Verifying your email address](/articles/verifying-your-email-address/)." {% endif %}If you need to update or add an email address to your GPG key, see "[Associating an email with your GPG key](/articles/associating-an-email-with-your-gpg-key)."