Update README.md

Added a line for createsuperuser for newbies to django like me to be able to get past the initial login screen 🤣

README.md

@@ -89,6 +89,10 @@ SECRET_KEY=[YOUR_SECRET_KEY]
 python manage.py migrate
 ```
 
+```bash
+python manage.py createsuperuser
+```
+
 ```bash
 python manage.py runserver
 ```