[docs] - Add DU to landing page (#17353)

## Summary & Motivation

This PR adds a link to Dagster University to the docs landing page.

## How I Tested These Changes

👀

docs/content/getting-started.mdx

@@ -10,15 +10,18 @@ You declare functions that you want to run and the data assets that those functi
 
 Dagster is built to be used at every stage of the data development lifecycle - local development, unit tests, integration tests, staging environments, all the way up to production.
 
-**New to Dagster**? Check out the **Hello Dagster example**, learn with some hands-on **Tutorials**, or dive into **Concepts**.
+**New to Dagster**? Check out the **Hello Dagster example**, learn with some hands-on **Tutorials**, or dive into **Concepts**. For an in-depth learning experience, enroll in **Dagster University**.
 
 <div className="inline-flex flex-row space-x-4">
-  <Button link="/getting-started/hello-dagster">Run Hello Dagster</Button>
+  <Button link="/getting-started/hello-dagster">Run Hello, Dagster!</Button>
+  <Button link="/tutorial" style="secondary">
+    View Tutorials
+  </Button>
   <Button link="/concepts" style="secondary">
     Explore Concepts
   </Button>
-  <Button link="/tutorial" style="secondary">
-    View Tutorials
+  <Button link="https://courses.dagster.io" style="secondary">
+    Enroll in Dagster University
   </Button>
 </div>