Merge pull request #4630 from plotly/gvwilson-patch-1

Update README.md with "maintained by Plotly" badge

Author: gvwilson

README.md

@@ -31,6 +31,13 @@
     </tr>
 </table>
 
+<div align="center">
+  <a href="https://dash.plotly.com/project-maintenance">
+    <img src="https://dash.plotly.com/assets/images/maintained-by-plotly.png" width="400px" alt="Maintained by Plotly">
+  </a>
+</div>
+
+
 ## Quickstart
 
 `pip install plotly==5.22.0`