The tree had only the bundled Kenney asset licenses (CC0), leaving the Ludic
compiler and runtime source implicitly all-rights-reserved (issue #36).
- Add a root `LICENSE`: Apache-2.0 — permissive, with the patent grant that
suits a language/compiler project.
- README: add a License section stating `SPDX-License-Identifier: Apache-2.0`
and clarifying that code (Apache-2.0) and the third-party CC0 Kenney art are
licensed separately. Also add a Contributing section linking CONTRIBUTING.md
and the Forgejo templates.
Closes#36
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>