Remove “official” from JavaScript.com (#6929)

public/roadmap-content/backend.json

@@ -224,7 +224,7 @@
         "type": "article"
       },
       {
-        "title": "Official JavaScript Documentation",
+        "title": "JavaScript Beginner Resources",
         "url": "https://www.javascript.com/",
         "type": "article"
       },
@@ -3047,4 +3047,4 @@
       }
     ]
   }
-}
+}