add free ebook notification

README.md

@@ -30,3 +30,7 @@ All the required information to get started with the respective recipes is menti
 
 ### Suggestions and Feedback
 [Click here](https://docs.google.com/forms/d/e/1FAIpQLSe5qwunkGf6PUvzPirPDtuy1Du5Rlzew23UBp2S-P3wB-GcwQ/viewform) if you have any feedback or suggestions.
+### Download a free PDF
+
+ <i>If you have already purchased a print or Kindle version of this book, you can get a DRM-free PDF version at no cost.<br>Simply click on the link to claim your free PDF.</i>
+<p align="center"> <a href="https://packt.link/free-ebook/9781788474443">https://packt.link/free-ebook/9781788474443 </a> </p>