Corrected URL

The original URL seems to have been changed.

Author: MrPaulAR

README.md

@@ -14,7 +14,7 @@
 
 ![Plot Dash Tutorial](https://storage.googleapis.com/hackersandslackers-cdn/2018/12/Dash@2x.jpg)
 
-Source code for the accompanying tutorial found here: https://hackersandslackers.com/gaining-full-control-over-plotly-dash/
+Source code for the accompanying tutorial found here: https://hackersandslackers.com/plotly-dash-with-flask/
 
 ## Getting Started