Add responsible disclosure policy (#11666)

Co-Authored-By: Sheri Bigelow <[email protected]>

Author: jkmassel

README.md

@@ -96,6 +96,10 @@ Read more about [OAuth2](https://developer.wordpress.com/docs/oauth2/) and the [
 
 Read our [Contributing Guide](CONTRIBUTING.md) to learn about reporting issues, contributing code, and more ways to contribute.
 
+## Security
+
+If you happen to find a security vulnerability, we would appreciate you letting us know at https://hackerone.com/automattic and allowing us to respond before disclosing the issue publicly.
+
 ## Getting in Touch ##
 
 If you have questions about getting setup or just want to say hi, join the [WordPress Slack](https://chat.wordpress.org) and drop a message on the `#mobile` channel.

SECURITY.md

@@ -0,0 +1,5 @@
+# Security Policy
+
+## Reporting a Vulnerability
+
+If you happen to find a security vulnerability, we would appreciate you letting us know at https://hackerone.com/automattic and allowing us to respond before disclosing the issue publicly.