title: Add statistical significance between two groups for categorical boxplot
body: <p>I would like to make a figure similar to the first screenshot (<a href="https://seaborn.pydata.org/tutorial/categorical.html" rel="nofollow noreferrer">https://seaborn.pydata.org/tutorial/categorical.html</a>), but I would like to add a t-test value in the form of a star at the top of each x value as seen in the second screenshot (<a href="https://github.com/jbmouret/matplotlib_for_papers" rel="nofollow noreferrer">https://github.com/jbmouret/matplotlib_for_papers</a>).
  <a href="https://i.stack.imgur.com/EWync.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EWync.png" alt="enter image description here"></a>
  What would be the best way to generalize this to being able to do multiple x values in the second screenshot while still maintaining the stars in the second screenshot for each comparison?
  <a href="https://i.stack.imgur.com/XRryI.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XRryI.png" alt="enter image description here"></a>
  Thanks!</p>