fix: Link to simple melody app

Author: ff6347

src/content/tutorials/en/custom-shapes-and-smooth-curves.mdx

@@ -554,4 +554,4 @@ Try one of our other tutorials:
 
 - [Creating and Styling HTML](/tutorials/creating-styling-html) (Web Design Chapter)
 - [Abracadabra: Speak With Your Hands](/tutorials/speak-with-your-hands) (ml5.js and p5.js)
-- [Melody App](/tutorials/melody-app-with-nodejs) (Node.js and p5.js)
+- [Simple Melody App](/tutorials/simple-melody-app/) (Node.js and p5.js)