Update Security Policy

Author: apragacz

SECURITY.md

@@ -7,10 +7,15 @@ currently being supported with security updates:
 
 | Version | Supported          |
 | ------- | ------------------ |
+| 0.9.x   | :white_check_mark: |
 | 0.8.x   | :white_check_mark: |
-| 0.7.x   | :white_check_mark: |
-| < 0.7.0 | :x:                |
+| < 0.8.0 | :x:                |
 
 ## Reporting a Vulnerability
 
-If you think that you found a security issue (especially one with high severity), please do not share it publicly; instead, write a [direct e-mail](mailto:[email protected]) to the author.
+If you think that you found a security issue (especially one with high severity),
+please do not share it publicly; instead do one of these:
+
+*   [Report a security vulnerability](https://github.com/apragacz/django-rest-registration/security/advisories/new)
+    via GitHub (preferred)
+*   Write a [direct e-mail](mailto:[email protected]) to the author.