Update README.md

Author: bungle

README.md

@@ -197,7 +197,7 @@ Or with Lua code like this:
 ```lua
 local session = require "resty.session".new()
 -- After new you cannot specify storage as a string, you need to give actual implementation
-session.storage = require "resty.sesstion.storage.shm"
+session.storage = require "resty.session.storage.shm"
 -- or
 local session = require "resty.session".new({ storage = "shm" })
 ```