Adding JavaScript Books (#6479)

* Adding ES5 to ESNext

* Update free-programming-books-langs.md

* Update books/free-programming-books-langs.md

Co-authored-by: David Ordás <3125580+davorpa@users.noreply.github.com>

* Update books/free-programming-books-langs.md

Co-authored-by: David Ordás <3125580+davorpa@users.noreply.github.com>

Co-authored-by: David Ordás <3125580+davorpa@users.noreply.github.com>

books/free-programming-books-langs.md

@@ -1115,6 +1115,7 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 * [JavaScript ES6 and beyond](https://github.com/AlbertoMontalesi/JavaScript-es6-and-beyond-ebook) - Alberto Montalesi (PDF, epub)
 * [JavaScript For Cats](http://jsforcats.com) - Maxwell Ogden (HTML)
 * [JavaScript for Impatient Programmers (ES2020 edition)](https://exploringjs.com/impatient-js/toc.html) - Dr. Axel Rauschmayer (HTML)
+* [JavaScript from ES5 to ESNext](https://flaviocopes.com/page/es5-to-esnext/) - Flavio Copes (PDF, EPUB, Kindle) *(email address requested)*
 * [JavaScript Fundamentals, Plus a Dash Of JQuery - for dinner ladies](http://nicholasjohnson.com/javascript-book/) - Nicholas Johnson (HTML)
 * [JavaScript Garden](http://bonsaiden.github.io/JavaScript-Garden/) Maintained by Tim Ruffles (HTML)
 * [JavaScript Interview #35](https://gumroad.com/l/javascript-interview-35) - Coderslang Master (PDF, email address *requested*, not required)
@@ -1140,6 +1141,7 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 * [Single page apps in depth](http://singlepageappbook.com) - Mixu (HTML)
 * [Speaking JavaScript](http://speakingjs.com/es5/) - Dr. Axel Rauschmayer
 * [Standard ECMA-262 ECMAScript 2016 Language Specification](https://www.ecma-international.org/publications/standards/Ecma-262.htm) - Ecma International (HTML,PDF)
+* [The JavaScript Beginner's Handbook](https://flaviocopes.com/page/javascript-handbook/) - Flavio Copes (PDF, EPUB, Kindle) *(email address requested)*
 * [The JavaScript Tutorial](http://javascript.info) - Ilya Kantor (HTML)
 * [The JavaScript Way](https://github.com/bpesquet/thejsway) - Baptiste Pesquet
 * [The Problem with Native JavaScript APIs](https://www.oreilly.com/programming/free/native-javascript-apis.csp) - Nicholas C. Zakas (PDF, email address *requested*)