Add dictionary methods to docs

docs/quickstart.rst

@@ -199,6 +199,24 @@ The only tricky one is unions, where you need to call `.which()` to determine th
             print('self employed')
         print()
 
+Dictionaries
+--------------
+
+Converting to a dictionary
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+There is a convenience method for converting Cap'n Proto messages to a dictionary. This works for both Builder and Reader type messages::
+
+    alice.to_dict()
+
+Reading froma dictionary
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+There is a convenience method for reading for reading a dict in and building a Builder message out of it. This the inverse of `Converting to a dictionary`_::
+
+    my_dict = {'name' : 'alice'}
+    alice = addressbook.Person.from_dict(my_dict)
+
 Full Example
 ------------------