This option provides a more convenient way to overlay dummy packages.
It also adds a function `config.lib.test.mkStubPackage` that can,
e.g., be used for `package` options.
`rbw` is a stand-alone Bitwarden client, which makes use of a daemon to
cache your password and manage state.
Its configuration can be managed by `home-manager` or not, leaving the
user free to configure it through `rbw config`.