problems(js): add “2667. Create Hello World Function”

Signed-off-by: Matej Focko <mfocko@redhat.com>

problems/create-hello-world-function.js

@@ -0,0 +1,13 @@
+/**
+ * @return {Function}
+ */
+var createHelloWorld = function() {
+    return function(...args) {
+        return "Hello World";
+    };
+};
+
+/**
+ * const f = createHelloWorld();
+ * f(); // "Hello World"
+ */