add more fresh-start instructions (#151)

Reviewed-on: Fediversity/Fediversity#151
Reviewed-by: kiara Grouwstra <kiara@procolix.eu>

panel/README.md

@@ -27,20 +27,30 @@ The Fediversity Panel is a web service for managing Fediversity deployments with
   manage
   ```
 
-- Run the server locally
+- With a fresh database, run:
+
+  ```
+  manage migrate
+  ```
+
+- Run the server locally:
 
   ```shell-session
   manage runserver
   ```
 
-- Whenever you add a field in the database schema, run:
+- Create an admin user:
 
-  ```console
+  ```shell-session
+  manage createsuperuser
+  ```
+
+  and log in at <http://localhost:8000/admin>.
+
+- After changing the database schema, add migrations and apply them:
+
+  ```shell-session
   manage makemigrations
-  ```
-
-  Then before starting the server again, run:
-
-  ```
   manage migrate
   ```
+