detect new system to register default admin

.env.example

@@ -1,6 +1,6 @@
 mongoURI=mongodb://localhost:27017
 dbo=school
-secret=
+secret=<your 256 bit secret>
 PORT=8000
-SYSTEM_EMAIL=
-SYSTEM_PASSWORD=
+SYSTEM_EMAIL=<your system email>
+SYSTEM_PASSWORD=<your system password>