Fix skill activation parse error by removing template literal example

Remove function example with template literal from SKILL.md that caused
bash parse errors when activating the modern-javascript skill. The
destructuring content is already covered in references/CHEATSHEET.md.

Author: ccheney

skills/modern-javascript/SKILL.md

@@ -269,11 +269,6 @@ const { address: { city, country } } = user;
 
 // Rest
 const { id, ...userData } = user;
-
-// Function parameters
-function greet({ name, greeting = 'Hello' }) {
-  return `${greeting}, ${name}!`;
-}
 ```
 
 ### Array Destructuring