Add the LICENSE file that package.json already declares

[zchee]

Hi — thanks for building opencode-cursor.

package.json declares "license": "MIT", but the repository contains no
LICENSE file, so GitHub reports the project as unlicensed and downstream
users have no full MIT text (with your copyright line) to rely on and
reproduce.

Would you add a standard MIT LICENSE file (e.g. Copyright (c) 2026 Ephraim Duncan) matching the package.json declaration?

Context: I'm building ganja, a Rust behavioral port of opencode
(https://github.com/zchee/ganja-code, Apache-2.0), and I'd like to derive
Cursor protocol knowledge from this plugin with proper MIT attribution in
our THIRD_PARTY_NOTICES. A LICENSE file in the repo makes that attribution
unambiguous for everyone downstream, not just us.

Thanks!