Create SECURITY.md (#2939)

Author: asbjornu

SECURITY.md

@@ -0,0 +1,32 @@
+# Security Policy
+
+## Supported Versions
+
+| Version   | Supported          |
+| --------: | :----------------: |
+| 5.x       | :white_check_mark: |
+| ⋜ 5.x     | :x:                |
+
+## Reporting Security Issues
+
+⚠ **Please do not report security vulnerabilities through public GitHub issues.** ⚠
+
+Instead, please send an email to [[email protected]](mailto:[email protected]).
+
+You should receive a response within 24 hours. If for some reason you do not, please follow up via email to ensure we received your original message.
+
+Please include the requested information listed below (as much as you can provide) to help us better understand the nature and scope of the possible issue:
+
+  * Type of issue (e.g. buffer overflow, SQL injection, cross-site scripting, etc.)
+  * Full paths of source file(s) related to the manifestation of the issue
+  * The location of the affected source code (tag/branch/commit or direct URL)
+  * Any special configuration required to reproduce the issue
+  * Step-by-step instructions to reproduce the issue
+  * Proof-of-concept or exploit code (if possible)
+  * Impact of the issue, including how an attacker might exploit the issue
+
+This information will help us triage your report more quickly.
+
+## Preferred Languages
+
+We prefer all communications to be in English.