title: Value of type 'URLQueryItem' has no member 'append'
body: <p>I don't see why I would be getting this error. It has to do with the <code>queryItems.append(queryItems)</code> line.</p>
  
  <pre><code>func request(endpoint: String,
               parameters: [String: Any],
               completion: @escaping (Result&lt;User, Error&gt;) -&gt; Void) {
  
      guard let url = URL(string: baseURL + endpoint) else {
          completion(.failure(NetworkingError.badURL))
          return
      }
  
      var request = URLRequest(url: url)
  
      var components = URLComponents()
  
      var queryItems = [URLQueryItem]()
  
      for (key, value) in parameters {
  
          let queryItems = URLQueryItem(name: key, value: String(describing: value))
          queryItems.append(queryItems) //ERROR Value of type 'URLQueryItem' has no member 'append'
      }
  </code></pre>