Clarified URL patterns in tutorial 3.

Co-authored-by: Nick Pope <nick@nickpope.me.uk>

docs/intro/tutorial03.txt

@@ -121,9 +121,10 @@ like so::
 
 The ``question_id=34`` part comes from ``<int:question_id>``. Using angle
 brackets "captures" part of the URL and sends it as a keyword argument to the
-view function. The ``:question_id>`` part of the string defines the name that
-will be used to identify the matched pattern, and the ``<int:`` part is a
+view function. The ``question_id`` part of the string defines the name that
+will be used to identify the matched pattern, and the ``int`` part is a
 converter that determines what patterns should match this part of the URL path.
+The colon (``:``) separates the converter and pattern name.
 
 Write views that actually do something
 ======================================