update manage.py commands

README.md

@@ -6,4 +6,7 @@ Nasazení na hostingu:
     $ cd hvezdarna
     $ virtualenv .venv
     $ pip install -r requirements.txt
-    $ ./manage.py migrate
+    $ python manage.py migrate
+    $ python manage.py collectstatic
+    $ python manage.py createsuperuser
+