Update CONTRIBUTING.md

Author: acburst

CONTRIBUTING.md

@@ -19,6 +19,7 @@
 - Make your changes
 - Submit a pull request with full remarks documenting your changes
 - Pull request MAY then be accepted by project creators
+- Make sure you are altering the correct source files (Never alter compiled / dist files)
 
 ## Jasmine Testing Guide
 **References:**
@@ -90,4 +91,4 @@ Try and keep your commit history clean and concise. Once you submit your pull re
     });
     ```
 
-    **Note:** If you add done as a callback, and you don’t call the `done()` function, it will stall forever and error after a max limit of around 5 seconds. 
+    **Note:** If you add done as a callback, and you don’t call the `done()` function, it will stall forever and error after a max limit of around 5 seconds.