title: Send discord webhook without jQuery
body: <p>I'm trying to send a discord webhook message without jQuery.
  I tried the following:</p>
  
  <pre><code>var sendWebhook = new XMLHttpRequest()
  
              sendWebhook.open("POST", $("webhook")[0].value)
              sendWebhook.onload = function() {
                  if(sendWebhook.status === 200) {
                      Leaderboard.sendMessage("Webhook sent!")
                  } else {
                      Leaderboard.sendMessage("Failed sending webhook...")
                  }
              }
              sendWebhook.send({
                  data: JSON.stringify({
                      content: "hi",
                      username: "hello",
                      avatar_url: ""
                  })
              })
  </code></pre>
  
  <p>and so much other ways but it always fail! What's the problem?
  Thanks!!</p>