docs(SECURITY): sync security policy

Author: caugner

.github/CODEOWNERS

@@ -10,3 +10,4 @@
 
 /.github/workflows/ @mdn/engineering
 /.github/CODEOWNERS @mdn/content-team @mdn/engineering
+/SECURITY.md @mdn/engineering

SECURITY.md

@@ -0,0 +1,13 @@
+# Security Policy
+
+## Reporting a Vulnerability
+
+If you've discovered a security issue, please report it through the form linked
+below, which will create a secure, private ticket.
+https://bugzilla.mozilla.org/form.web.bounty
+
+MDN may be eligible for
+[Mozilla's Security Bug Bounty Program](https://www.mozilla.org/en-US/security/bug-bounty/).
+You can find more information about the bounty program in the
+[Mozilla Web Bug Bounty FAQ](https://www.mozilla.org/en-US/security/bug-bounty/faq-webapp/).
+You can use the above form even if you are not interested in a bounty reward.