title: How can I draw something in the background of a ggplot?
body: <p>I'm working on making shot charts for basketball. I need to figure out how to actually draw the outline of a basketball court in the background. Any ideas?</p>
  
  <p><img src="https://i.stack.imgur.com/YnEt0.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/7j4Oy.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/qzlUw.png" alt="enter image description here"></p>