readme updated for new release

readme.md

@@ -3,7 +3,7 @@
 An open source book about how to contribute to open source.  
 I already said open source?
 
-[Release article](https://daniele.tech/2019/10/contribute-to-opensource-the-right-way-book/)
+[Release article 2nd edition](https://daniele.tech/2020/07/contribute-to-open-source-the-right-way-2nd-edition-download-the-free-open-book-now) - [Release article 1st edition](https://daniele.tech/2019/10/contribute-to-opensource-the-right-way-book/)
 
 ## Description 
 Have you ever wondered how the open source world exists thanks to the contribution of thousands of people all over the world? Is there a way to learn the skills to contribute at maximum, or to improve it? 
@@ -16,4 +16,4 @@ Join the revolution means be an active part of it in all the sides of this world
 
 Be a part of the open source world can be the 21 century skills that you deserve?
 
-Check the [pdf/epub/mobi version on Leanpub](https://leanpub.com/contributetoopensource-therightway/) or on [GitHub](https://github.com/Mte90/Contribute-to-opensource-the-right-way/releases/tag/2019.1) for free.
+Check the [pdf/epub/mobi version on Leanpub](https://leanpub.com/contributetoopensource-therightway/) or on [GitHub](https://github.com/Mte90/Contribute-to-opensource-the-right-way/releases/tag/2020.1) for free.