:pencil: extra docker command

readme.md

@@ -64,6 +64,7 @@ git clone git@github.com:wagtail/bakerydemo.git
 cd bakerydemo
 docker-compose up --build -d
 docker-compose run app /venv/bin/python manage.py load_initial_data
+docker-compose up
 ```
 
 The demo site will now be accessible at [http://localhost:8000/](http://localhost:8000/) and the Wagtail admin