chore: add initial SECURITY.md (backstage#527)

Signed-off-by: Beth Griggs <bethanyngriggs@gmail.com>

SECURITY.md

@@ -0,0 +1,13 @@
+# Security Policy
+
+## Reporting a Vulnerability
+
+If you discover a potential security vulnerability within this repository, please report it through the GitHub reporting interface.
+
+1. Click on the [Security](https://github.com/backstage/community-plugins/security) tab on this repository
+2. Select **Report a vulnerability**.
+3. Provides the necessary information and submit your report. Please ensure you include the name of the effected workspace or plugin.
+
+For vulnerabilities in the core Backstage project, please follow their [security policy](https://github.com/backstage/backstage/blob/master/SECURITY.md). For vulnerabilities in third-party dependencies, please follow the respective processes outlined by those projects.
+
+If you are unsure, please reach out to one of the  [Community Plugins Maintainers](https://github.com/backstage/backstage/blob/master/OWNERS.md#community-plugins) on Discord.