Update free-programming-books.md (#2904)

* Update free-programming-books.md

About author:
https://www.amazon.com/default/e/B001IXTSLU/ref=dp_byline_cont_book_1?redirectedFromKindleDbs=true
https://en.wikipedia.org/wiki/Mark_Burgess_(computer_scientist)

* Update free-programming-books.md

free-programming-books.md

@@ -587,6 +587,7 @@
 
 #### Operating systems
 
+* [A short introduction to operating systems (2001)](http://markburgess.org/os/os.pdf) - Mark Burgess (PDF)
 * [Computer Science from the Bottom Up](http://www.bottomupcs.com)
 * [How to Make a Computer Operating System ](https://github.com/SamyPesse/How-to-Make-a-Computer-Operating-System) (:construction: *in process*)
 * [How to write a simple operating system in assembly language](http://mikeos.sourceforge.net/write-your-own-os.html) - Mike Saunders (HTML)