Update README.md

Author: johntyree

README.md

@@ -3,33 +3,37 @@ python-patterns
 
 A collection of design patterns implemented (by other people) in python.
 
+When an implementation is added or modified, be sure to update this file and
+rerun `append_output.sh` to keep the output comments at the bottom up to date.
+
 Current Patterns:
 
 * 3-tier
+* abstract_factory
+* adapter
+* borg
+* bridge
+* builder
+* catalog
+* chain
+* command
 * composite
-* mvc
 * decorator
-* null
 * facade
-* observer
-* abstract_factory
 * factory_method
-* pool
-* adapter
 * flyweight
+* graph_search
+* iterator
+* mediator
+* memento
+* mvc
+* null
+* observer
+* pool
 * prototype
-* borg
 * proxy
-* bridge
-* graph_search
+* publish_subscribe
 * state
-* builder
-* iterator
 * strategy
-* chain
-* mediator
 * template
-* command
-* memento
 * visitor
-* publish_subscribe