Add absolute import example (#17342)

Might be easier for some users to see a whole app set up with it

docs/advanced-features/module-path-aliases.md

@@ -4,6 +4,13 @@ description: Configure module path aliases that allow you to remap certain impor
 
 # Absolute Imports and Module path aliases
 
+<details>
+  <summary><b>Examples</b></summary>
+  <ul>
+    <li><a href="https://github.com/vercel/next.js/tree/canary/examples/with-absolute-imports">With env</a></li>
+  </ul>
+</details>
+
 Next.js automatically supports the `tsconfig.json` and `jsconfig.json` `"paths"` and `"baseUrl"` options since [Next.js 9.4](https://nextjs.org/blog/next-9-4).
 
 > Note: `jsconfig.json` can be used when you don't use TypeScript