add $10 campaign

Author: packtutkarshr

README.md

@@ -1,2 +1,6 @@
+## [Get this title for $10 on Packt's Spring Sale](https://www.packt.com/V16455?utm_source=github&utm_medium=packt-github-repo&utm_campaign=spring_10_dollar_2022)
+-----
+For a limited period, all eBooks and Videos are only $10. All the practical content you need \- by developers, for developers
+
 # Reactive-Programming-in-Java-Using-RxJava-3.x-ReactiveX
 Reactive Programming in Java Using RxJava 3.x: ReactiveX by Packt Publishing