rST formatting

docs/publish.rst

@@ -139,7 +139,7 @@ You can now run the resulting container like so::
 
 This exposes port 8001 inside the container as port 8081 on your host machine, so you can access the application at ``http://localhost:8081/``
 
-You can customize the port that is exposed by the countainer using the ``--port`` option:
+You can customize the port that is exposed by the countainer using the ``--port`` option::
 
     datasette package mydatabase.db --port 8080