message: Add retrofit instructions
diff: ---
  Adds "yarn dev" command to simplify local development.
  +
  +To add the command to an existing application, first add it to the `scripts`
  +section of your monorepo root `package.json` like so:
  +
  +```diff
  + "scripts": {
  ++ "dev": "concurrently \"yarn start\" \"yarn start-backend\"",
  + "start": "yarn workspace app start",
  + "start-backend": "yarn workspace backend start",
  +```
  +
  +And then add the `concurrently` package to your monorepo, like so:
  +
  +```sh
  +yarn add concurrently@6.0.0 --dev -W
  +```
  +
  +Notes:
  +
  +- This needs to be done to the monorepo root, not your frontend or backend package.
  +- The `--dev -W` will add it only to `devDependencies`, and force it to the monorepo main root.
  +
  +You can then run `yarn dev` which will start both the Backstage frontend and backend in a single window.
  