readme: change the sambal start command order in readme

The python -m method doesn't have a problem when ctrl+c is pressed, the entrypoint script does.

There is an issue with the entrypoint method when ctrl+c is pressed and a ticket has been opened for this (issue #51)

Show the python -m command first in the meantime.

README.md

@@ -29,11 +29,11 @@ Starting Sambal
 
 To start a development server just run:
 
-    sambal
+    python -m sambal
 
-or running as a module does the same:
+Or use the entrypoint installed into the virtualenv:
 
-    python -m sambal
+    sambal
 
 The web interface can then be accessed at http://localhost:8000