more docs.

Author: agentzh

README.md

@@ -17,11 +17,15 @@ servers (like Kyoto Tycoon). Each NGINX or OpenResty server node simply queries
 Memcached server(s) with a key containing the timestamp every hour. It has the following
 advantages:
 
+1. We keep a list of keys and only evict the oldest key every hour, which allows
+gradual phase-out of old keys.
+1. The keys are updated automatically for all the virtual (SSL) servers defined in the `nginx.conf` file.
+1. No NGINX server reload or restart is needed. New keys are pulled from Memcached or
+Memcached-compatible servers automatically every hour.
 1. All network I/O is 100% nonblocking, that is, it never blocks any OS threads nor the nginx event loop.
+1. All the core logic is in pure Lua, which is every easy to hack and adjust for special requirements.
 1. Uses shm cache for the keys so that only one worker needs to query the Memcached or
 Memcached-compatible servers.
-1. We keep a list of keys and only evict the oldest key every hour, which allows
-gradual phase-out of old keys.
 
 Installation
 ============