doc: update doc

Author: fffonion

README.md

@@ -45,7 +45,7 @@ Synopsis
 
 Shared dictionaries defined in `http` and `stream` subsystems are not shared to each other *currently*, thus we need two sets of configurations to debug with either subsystem. 
 
-However there're [patches](patches) if you want to share shdict between `http` and `stream` subsystems. After apply the patch, you will need to use two `lua_shared_dict` directive to define shared dict twice with same name and size. e.g.:
+However there're [patches](patches) if you want to share shdict between `http` and `stream` subsystems. After apply the patch, you will need to use two `lua_shared_dict` directives to define shared dict twice with same name and same size. e.g.:
 
 ```lua
 http {
@@ -57,6 +57,7 @@ stream {
 }
 ```
 
+This module provide a similar API to use in both subsystems.
 
 http
 ----