Add book Pull Requests and Code Review (#10487)

* Add book Pull Requests and Code Review

* Remove formats

Co-authored-by: Eric Hellman <eric@hellman.net>

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Co-authored-by: Eric Hellman <eric@hellman.net>

books/free-programming-books-subjects.md

@@ -228,6 +228,7 @@ Books that cover a specific programming language can be found in the [BY PROGRAM
 * [Computer Science I](https://cse.unl.edu/~cbourke/ComputerScienceOne.pdf) - Chris Bourke (PDF)
 * [Computer Science II](https://cse.unl.edu/~cbourke/ComputerScienceTwo.pdf) - Chris Bourke (PDF)
 * [CS Principles: Big Ideas in Programming](https://www.openbookproject.net/books/StudentCSP/) - Mark Guzdial, Barbara Ericson (HTML)
+* [Pull Requests and Code Review](https://scs.tl/book-pr) – Sebastien Castiel
 * [What to Look for in a Code Review](https://leanpub.com/whattolookforinacodereview) - Trisha Gee (HTML, PDF, EPUB, Kindle) *(Leanpub account or valid email requested)*