Update README.md

@@ -2,12 +2,13 @@ simple-rtmp-server
 ==================
 
 simple rtmp origin/edge live server over state-threads.
+can be used as origin server, or rtmp-server for encoder.
 
 1. simple: also stable enough.
 2. high-performance: single-thread, async socket, event/st-thread driven.
 3. support origin and edge mode.
 4. only for live streaming.
-5. donot support vhost.
+5. donot support vhost, __defaultVhost__ only.
 6. single process, no multiple processes yet.
 
 Winlin