react links doesnt exists in gitbook (#5546)

* react links doesnt exists in gitbook

* change link

* change order

* add link

* removed trailing slash

books/free-programming-books.md

@@ -1961,8 +1961,8 @@ Kerridge (PDF) (email address *requested*, not required)
 * [Learning React.js: Getting Started and Concepts](https://scotch.io/tutorials/learning-react-getting-started-and-concepts)
 * [React-Bits](https://github.com/vasanthk/react-bits)
 * [React Book, your beginner guide to React](https://github.com/softchris/react-book/) - Chris Noring
-* [React Enlightenment](https://www.gitbook.com/book/frontendmasters/react-enlightenment/details)
-* [React In-depth: An exploration of UI development](https://www.gitbook.com/book/developmentarc/react-indepth/details)
+* [React Enlightenment](https://www.reactenlightenment.com)
+* [React In-depth: An exploration of UI development](https://developmentarc.gitbooks.io/react-indepth/content/)
 * [React JS Notes for Professionals](https://goalkicker.com/ReactJSBook/) - Compiled from StackOverflow Documentation (PDF)
 * [React Primer Draft](https://github.com/mikechau/react-primer-draft)
 * [React Succinctly](https://www.syncfusion.com/ebooks/react-succinctly) - Samer Buna