Migrate launcher configuration from JSON to TOML format, add new `launcher.toml` and `mods.toml` files, remove `launcher.json`, and update project metadata in `pyproject.toml` to version 0.2.0.
Migrate launcher configuration from JSON to TOML format, add new `launcher.toml` and `mods.toml` files, remove `launcher.json`, and update project metadata in `pyproject.toml` to version 0.2.0.