chore: add Security Policy

Author: rutajdash

SECURITY.md

@@ -0,0 +1,15 @@
+# Security Policy
+
+## Supported Versions
+
+- Version 1.0.x is the latest version.
+- Version 0.x.x are initial development versions.
+
+| Version | Supported          |
+| ------- | ------------------ |
+| 1.0.x   | :white_check_mark: |
+| < 1.0   | :x:                |
+
+## Reporting a Vulnerability
+
+- To report a vulnerability, create an issue with the label "vulnerability" or [click here](https://github.com/rutajdash/prettier-cli-action/issues/new?assignees=&labels=vulnerability&template=vulnerability_report.md&title=bug%3A+).