Add auxiliary verb

"How engines work?" is grammatically incorrect

Author: h3xar0n

1-js/01-getting-started/1-intro/article.md

@@ -30,7 +30,7 @@ Different engines have different "codenames", for example:
 
 The terms above are good to remember, because they are used in developer articles on the internet. We'll use them too. For instance, if "a feature X is supported by V8", then it probably works in Chrome and Opera.
 
-```smart header="How engines work?"
+```smart header="How do engines work?"
 
 Engines are complicated. But the basics are easy.