Better README

Author: Bill Wang

README.md

@@ -15,7 +15,7 @@ If you're new to stacker you may use `stacker_cookiecutter <https://github.com/c
 
 Make sure you have permission to access aws, review below files if you need change anything.
 
-1) Adjust namespace to a global unique name, the name in example will be used as s3 bucket name, and has been used. 
+1) Adjust namespace to a global unique name, the name in example will be used in s3 bucket name, and has been used. 
 2) I have issue to start with pre_build task, if you get same problem, comment that session. 
 
     config/stage.env