Attribute Macro node_bindgen

#[node_bindgen]

This turns regular rust function into N-API compatible native module

For example; given rust following here

fn sum(first: i32, second: i32) -> i32 {
     return first+second
}

into N-API module

#[no_mangle]
pub extern "C" fn n_sum(env: napi_env, cb_info: napi_callback_info) -> napi_value {
    fn sum(first: i32, second: i32) -> i32 {
      return first+second
    }
    let js_env = JsEnv::new(env);
    let js_cb = result_to_napi!(js_env.get_cb_info(cb_info, 2),&js_env);
    let first = result_to_napi!(js_cb.get_value::<i32>(0),&js_env);
    let second = result_to_napi!(js_cb.get_value::<i32>(0),&js_env);
    sum(msg).into_js(&js_env)
}