Update README.md

Author: mmcky

README.md

@@ -16,4 +16,8 @@ Stachurski](https://johnstachurski.net/).
 The PDF is available in `pdf/dp.pdf`
 
 Comments and feedback are very welcome.
-The easiest way to provide feedback is to open an issue above.
+The easiest way to provide feedback is to open an issue above.
+
+## Website
+
+This repository hosts the public book website.