chore: add SECURITY.md

Author: panva

SECURITY.md

@@ -0,0 +1,14 @@
+# Security Policy
+
+## Supported Versions
+
+The following major versions are currently supported with security updates.
+
+| Version                                                  | Security Fixes 🔑 |
+| -------------------------------------------------------- | ----------------- |
+| [v6.x](https://github.com/panva/openid-client/tree/v6.x) | ✅                |
+| [v5.x](https://github.com/panva/openid-client/tree/v5.x) | ✅                |
+
+## Reporting a Vulnerability
+
+You should report vulnerabilities using the [Github UI](https://github.com/panva/openid-client/security/advisories/new) or via email panva.ip@gmail.com