Multi line editing is no longer experimental.

It is now the default in the Redis command line interface so it is
used by many users every day.
diff --git a/README.markdown b/README.markdown
index 98ad7ff..2d21dc4 100644
--- a/README.markdown
+++ b/README.markdown
@@ -3,8 +3,7 @@
 A minimal, zero-config, BSD licensed, readline replacement used in Redis,
 MongoDB, and Android.
 
-* Single line editing mode with the usual key bindings implemented.
-* Experimental multi-line editing mode.
+* Single and multi line editing mode with the usual key bindings implemented.
 * History handling.
 * Completion.
 * About 1,100 lines of BSD license source code.