Customer info on how to request an advisory credit (#18356)

* Customer info on how to request an advisory credit

A location for support to point customers to if/when they ask to be credited for a security advisory

* Update content/code-security/security-advisories/editing-a-security-advisory.md

Co-authored-by: Leona B. Campbell <3880403+runleonarun@users.noreply.github.com>

Co-authored-by: Sarah Edwards <skedwards88@github.com>
Co-authored-by: Leona B. Campbell <3880403+runleonarun@users.noreply.github.com>

Author: 3 people

content/code-security/security-advisories/editing-a-security-advisory.md

@@ -17,6 +17,8 @@ You can credit people who helped discover, report, or fix a security vulnerabili
 
 If someone accepts credit, the person's username appears in the "Credits" section of the security advisory. Anyone with read access to the repository can see the advisory and the people who accepted credit for it.
 
+If you believe you should be credited for a security advisory, please contact the person who created the advisory and ask them to edit the advisory to include your credit. Only the creator of the advisory can credit you, so please don't contact GitHub Support about credits for security advisories.
+
 ### Editing a security advisory
 
 {% data reusables.repositories.navigate-to-repo %}