added link to updated course

Author: dtauer

README.md

@@ -1,3 +1,6 @@
+> [!NOTE]
+> This repo is from an archived version of the course. Watch the latest version of the course on [frontendmasters.com](https://frontendmasters.com/courses/service-workers/).
+
 # Service Workers & Offline Course by Kyle Simpson
 
 Code for the Web Workers section of the Service Workers and Offline course by Kyle Simpson.
@@ -6,4 +9,4 @@ Code for the Web Workers section of the Service Workers and Offline course by Ky
 
 To get started, download the [Starter Files (ZIP)](https://static.frontendmasters.com/resources/2019-05-10-service-worker-pwa/service-workers-starter.zip)
 
-Don't forget to `npm install` the necessary modules.
+Don't forget to `npm install` the necessary modules.