Update README

Author: machadoit

README.md

@@ -54,6 +54,8 @@ Then set it in your terminal, replacing %Project_Token% with your own token:
 export CODACY_PROJECT_TOKEN=%Project_Token%
 ```
 
+> Note: You should keep your API token well **protected**, as it grants owner permissions to your projects.
+
 Next, simply run the Codacy sbt plugin. It will find the current commit and send all details to your project dashboard:
 
 ```