[docs] Add SECURITY.md (#15804)

* [docs] Add SECURITY.md

* use material.ui.org@gmail.com

* Update SECURITY.md

Co-Authored-By: Josh Wooding <12938082+joshwooding@users.noreply.github.com>

* reviews

SECURITY.md

@@ -0,0 +1,15 @@
+# Security Policy
+
+## Supported Versions
+
+The versions of the project that are currently supported with security updates.
+
+| Version | Supported          |
+| ------- | ------------------ |
+| 4.x | :white_check_mark: |
+| 3.x | :white_check_mark: |
+| < 3.0 | :x: |
+
+## Reporting a Vulnerability
+
+You can report a vulnerability by contacting us via email at [security@material-ui.com](mailto:security@material-ui.com).