Add security policy

SECURITY.md

@@ -0,0 +1,15 @@
+# Security Policy
+
+## Supported Versions
+
+Only the latest version is supported with security updates.
+Note that version 1.x (webfuse legacy) is no longer maintained.
+
+| Version | Supported          |
+| ------- | ------------------ |
+| 2.0.x   | :white_check_mark: |
+| < 2.0   | :x:                |
+
+## Reporting a Vulnerability
+
+Please use the [Security tab](https://github.com/falk-werner/webfuse/security) to report vulnerabilities.