Create SECURITY.md (#1184)

## Checklist

- [ ] I have added
[tests](https://www.cursorless.org/docs/contributing/test-case-recorder/)
- [ ] I have updated the
[docs](https://github.com/cursorless-dev/cursorless/tree/main/docs) and
[cheatsheet](https://github.com/cursorless-dev/cursorless/tree/main/cursorless-talon/src/cheatsheet)
- [ ] I have not broken the cheatsheet

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Andreas Arvidsson <[email protected]>

Author: 3 people

Diff for: SECURITY.md

@@ -0,0 +1,9 @@
+# Security Policy
+
+## Supported Versions
+
+Cursorless is still pre-1.0, and users are expected to use the latest version, so security vulnerabilities are only patched on the latest version. If you would like security patches on an older version, please [open a discussion](https://github.com/cursorless-dev/cursorless/discussions/new).
+
+## Reporting a Vulnerability
+
+Please use the GitHub private security vulnerability [reporting system](https://github.com/cursorless-dev/cursorless/security/advisories/new).