adding a Learn module for APIs

7-bank-project/3-data/README.md

@@ -111,6 +111,8 @@ navigate('/dashboard');
 
 ✅ Did you know that by default, you can only call server APIs from the *same domain and port* than the web page you are viewing? This is security mechanism enforced by browsers. But wait, our web app is running on `localhost:3000` whereas the server API is running on ` localhost:5000`, why does it work? By using a technique called [Cross-Origin Resource Sharing (CORS)](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS), it is possible to perform cross-origin HTTP requests if the server adds special headers to the response, allowing exceptions for specific domains.
 
+> Learn more about APIs by taking this [lesson](https://docs.microsoft.com/en-us/learn/modules/use-apis-discover-museum-art?WT.mc_id=academic-4621-cxa)
+
 ## Update HTML to display data
 
 Now that we have the user data, we have to update the existing HTML to display it. We already know how to retrieve an element from the DOM using for example `document.getElementById()`. After you have a base element, here are some APIs you can use to modify it or add child elements to it: