Update README.md

README.md

@@ -10,6 +10,8 @@ When viewing pages on your machine, your browser will probably prevent loading J
 Instead of changing your security policy, you can run a local server, e.g. Python’s built-in http server.
 1. From the command line, run `python -m http.server` (this is for Python 3.x).
 1. In a browser, open [http://localhost:8000/](http://localhost:8000/) and navigate to the pages.
+Sometimws you need to force browser to load fresh content (instead of showing a cached version of the pages). In Crome on mac, hold down Shift
+while reloading.
 
 ## Content
 Some of the helping files are: