fix(guide): missing ] (#2933)

Author: brancobruyneel

guide/src/reference/attributes/on-js-imports/js_name.md

@@ -77,7 +77,7 @@ Could be accessed using this definition in Rust:
 ```rust
 #[wasm_bindgen(module = "bar")]
 extern "C" {
-    #[wasm_bindgen(js_name = default)
+    #[wasm_bindgen(js_name = default)]
     type Foo;
     #[wasm_bindgen(constructor, js_class = default)]
     pub fn new() -> Foo;