title: How to start with the first axis tick at the origin in ggplot
body: <p>I would like to always start with the first axis tick at the origin, such as in this image: </p>
  
  <p><a href="https://i.stack.imgur.com/edLFd.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/edLFd.png" alt="enter image description here"></a></p>
  
  <p>Playing around with <code>xlim</code>, <code>expand_limits</code> or <code>scale_x_continuous</code> doesn't really work - there's always a little spacing between first axis tick and origin. There should be an easy way to do this. Many thanks in advance.</p>