add short titles to frontmatter (#20131)

content/github/authenticating-to-github/connecting-to-github-with-ssh/adding-a-new-ssh-key-to-your-github-account.md

@@ -10,6 +10,7 @@ versions:
   ghae: '*'
 topics:
   - SSH
+shortTitle: Add a new SSH key
 ---
 Before adding a new SSH key to your {% data variables.product.product_name %} account, you should have:
 * [Checked for existing SSH keys](/articles/checking-for-existing-ssh-keys)

content/github/authenticating-to-github/connecting-to-github-with-ssh/checking-for-existing-ssh-keys.md

@@ -10,6 +10,7 @@ versions:
   ghae: '*'
 topics:
   - SSH
+shortTitle: Check for existing SSH key
 ---
 {% data reusables.ssh.dsa-support %}
 

content/github/authenticating-to-github/connecting-to-github-with-ssh/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent.md

@@ -12,6 +12,7 @@ versions:
   ghae: '*'
 topics:
   - SSH
+shortTitle: Generate new SSH key
 ---
 ## About SSH key generation
 

content/github/authenticating-to-github/connecting-to-github-with-ssh/index.md

@@ -23,5 +23,6 @@ children:
   - /adding-a-new-ssh-key-to-your-github-account
   - /testing-your-ssh-connection
   - /working-with-ssh-key-passphrases
+shortTitle: Connect with SSH
 ---
 

content/github/authenticating-to-github/connecting-to-github-with-ssh/testing-your-ssh-connection.md

@@ -10,6 +10,7 @@ versions:
   ghae: '*'
 topics:
   - SSH
+shortTitle: Test your SSH connection
 ---
 Before testing your SSH connection, you should have:
 - [Checked for existing SSH keys](/articles/checking-for-existing-ssh-keys)

content/github/authenticating-to-github/connecting-to-github-with-ssh/working-with-ssh-key-passphrases.md

@@ -12,6 +12,7 @@ versions:
   ghae: '*'
 topics:
   - SSH
+shortTitle: SSH key passphrases
 ---
 With SSH keys, if someone gains access to your computer, they also gain access to every system that uses that key. To add an extra layer of security, you can add a passphrase to your SSH key. You can use `ssh-agent` to securely save your passphrase so you don't have to reenter it.