Would you consider adding a LICENSE file? #23

Hi! We depend on CodeEditSymbols in a small macOS app and want to ship it
with correct attribution for the packages we bundle.

This repository doesn't currently have a LICENSE file, and there's no license
statement in the README — so there's no explicit grant covering redistribution
of the package inside a distributed application. The sibling repos in the org
(CodeEdit, CodeEditSourceEditor) are MIT, so we suspect that's the intended
license here too and the LICENSE file just hasn't been added yet.

Would the team be open to adding the org's standard MIT LICENSE? It would let
downstream apps like ours reproduce the required attribution correctly.

We're also contributing fixes upstream — see #22 — so we're invested in the
package's health.

Thanks so much!