title: Removing Kivy's Window border
body: <p>According to the kivy document, I can remove Window's border by <code>Window.borderless = True</code>
  (<a href="https://kivy.org/doc/stable/api-kivy.core.window.html" rel="nofollow noreferrer">https://kivy.org/doc/stable/api-kivy.core.window.html</a>)</p>
  
  <p>However, The problem is, it still shows the border when it starts up, then it gets removed in like 0.5 second. And it seems a bit weird to me</p>
  
  <p>Is it possible to remove the border at the very beginning?</p>