Add: Added JavaScript book (#7364)

* Add: Added JavaScript book

Modern JavaScript book added

* JavaScript book added

books/free-programming-books-langs.md

@@ -1098,6 +1098,7 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 * [Learning JavaScript Design Patterns](http://addyosmani.com/resources/essentialjsdesignpatterns/book/) - Addy Osmani (HTML)
 * [Let's Learn ES6](https://bubblin.io/cover/let-s-learn-es6-by-ryan-christiani#frontmatter) - Ryan Christiani (Superbook format)
 * [Managing Space and Time with JavaScript - Book 1: The Basics](http://www.noelrappin.com) - Noel Rappin (dead link)
+* [Modern JavaScript](https://www.modernjs.com) - Daniel Rubio
 * [Mozilla Developer Network's JavaScript Guide](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide) - Mozilla Developer Network contributors (HTML)
 * [Neural Networks with JavaScript Succinctly](https://www.syncfusion.com/ebooks/neural-networks-with-javascript-succinctly) - James McCaffrey (PDF, EPUB, MOBI)
 * [Oh My JS](https://web.archive.org/web/20150317231950/https://leanpub.com/ohmyjs/read) - Azat Mardanov (HTML)