Update: 15-function-expressions-arrows/article.md

This code snippet should be shown with the semicolon:
// Function Expression
let sum = function(a, b) {
  return a + b;
}

1-js/02-first-steps/15-function-expressions-arrows/article.md

@@ -195,7 +195,7 @@ First, the syntax: how to see what is what in the code.
     // Function Expression
     let sum = function(a, b) {
       return a + b;
-    }
+    };
     ```
 
 The more subtle difference is *when* a function is created by JavaScript engine.