Added Security Policy

SECURITY.md

@@ -0,0 +1,21 @@
+# Security Policy
+
+## Supported Versions
+
+Currently all work on this project goes into the nightly builds.
+4.2's RELEASE build is now quite old and should be considered legacy.
+We urge users to use the nightly releases, because the project
+constantly sees fixes.
+
+| Version       | Supported          |
+| ------------- | ------------------ |
+| 4.2 Nightlies | :white_check_mark: |
+| 4.2 Release   | :x:                |
+| < 4.2         | :x:                |
+
+## Reporting a Vulnerability
+
+Please file an issue in our GitHub's repo, because this app
+isn't meant to be safe to run as public instance yet, but rather as a LAN facing app.
+
+We welcome PRs and help in general in making YTDL-M more secure, but it's not a priority as of now.