Document subscribe() regexp syntax (#56)

Author: edenhill

confluent_kafka/src/Consumer.c

@@ -416,6 +416,11 @@ static PyMethodDef Consumer_methods[] = {
 	  "\n"
 	  "  Set subscription to supplied list of topics\n"
 	  "  This replaces a previous subscription.\n"
+          "\n"
+          "  Regexp pattern subscriptions are supported by prefixing "
+          "the topic string with ``\"^\"``, e.g.::\n"
+          "\n"
+          "    consumer.subscribe([\"^my_topic.*\", \"^another[0-9]-?[a-z]+$\", \"not_a_regex\"])\n"
 	  "\n"
 	  "  :param list(str) topics: List of topics (strings) to subscribe to.\n"
 	  "  :param callable on_assign: callback to provide handling of "