* Update free-programming-books-subjects.md

* Update free-programming-books-subjects.md

* Update free-programming-books-subjects.md

* Update free-programming-books-subjects.md

* Update free-programming-books-subjects.md

* Update free-programming-books-subjects.md

* Added a book under Computer Organization

Hey, I added one more free book under the subject. It's a pretty broad category and I am sure more free books exist on the topic. I personally studied from the book by Smruti Sarang and felt that it's too precious a resource to not share. I think COA deserves a separate category not only because it is a college course but also because COA gives a first introduction to the implementation of digital systems inside computers (boolean algebra, latches, mux, registers) before focusing on Assembly languages like x86 and ARM. I skimmed through your misc list but since the subject doesn't focus on programming languages hence we cannot add the existing books like 'Scientific Programming and Computer Architecture' in it.