update README.md

Author: xingjian-zhang

README.md

@@ -32,6 +32,8 @@ This is a **light**, **pure** and **convenient** commandline dictionary that hel
 python setup.py install
 ```
 
+**Note**: Do not use `pip install cmdict` because there is a package called `cmdict` written by others in the pip repo. By doing this you will download the wrong package. I am still looking for workaround for this.
+
 ## Run
 
 ```