This rebrands the CLI tool to 'naj' (Old Chinese reconstruction for "Me/I").
This name was chosen for better typing ergonomics (R-L-R alternation) and
availability on crates.io.
Changes:
- Update `Cargo.toml` package name to `naj`.
- Update binary name target to `naj`.
- Update documentation and README to reflect the new identity.
BREAKING CHANGE: The binary name is now `naj`. Users must update their
scripts and usage from `gosh` to `naj`.