Added Atomic Design book into free-programming-books-subjects.md (#8519)

books/free-programming-books-subjects.md

@@ -542,6 +542,7 @@ Books that cover a specific programming language can be found in the  [BY PROGRA
 * [A MACHINE MADE THIS BOOK ten sketches of computer science](http://ocaml-book.com/s/popbook.pdf) - JOHN WHITINGTON (PDF)
 * [Ansible Up & Running (first three chapters)](https://www.ansible.com/ebooks) *(account required)*
 * [Asterisk™: The Definitive Guide](http://solmu.org/pub/help/Asterisk/3nd_Edition_for_Asterisk_1.8) - Leif Madsen, Jim Van Meggelen, Russell Bryant (HTML)
+* [Atomic Design](https://atomicdesign.bradfrost.com) - Brad Frost
 * [Barcode Overview](http://www.tec-it.com/download/PDF/Barcode_Reference_EN.pdf) (PDF)
 * [Come, Let's Play: Scenario-Based Programming Using Live Sequence Charts](http://www.wisdom.weizmann.ac.il/~playbook/) - David Harel, Rami Marelly
 * [Communicating Sequential Processes](http://www.usingcsp.com/cspbook.pdf) - Tony Hoare (PDF)