message: Update changeset message for the cli package.
diff: '@backstage/cli': patch
  ---
  -Adds support for two new CLI options on the `repo build` and `package build` commands. Both options are only available to frontend components. Backend config continues to be supplied at runtime.
  -
  -CLI options take precedent over provided config.
  -
  -The new options are meant to add greater support for running the same bundle in multiple environments, ex: test, stage and prod.
  -`--publicPath`: Frontend route to host the app on, can be relative or absolute.
  -`--backendUrl`: Backend URL that the {backend.basePath}, e.g. /api, endpoint can be reached on. Can be relative or absolute.
  +Allow relative URLs to be passed as config values for `app.baseUrl` and `backend.baseUrl`, ie `app.baseUrl` can be `/`. Relative URLs are only supported for frontend builds, the backend still needs the full URL defined before run time.
  