Add The Mathematical Engineering of Deep Learning book (#11027)

* Add The Mathematical Engineering of Deep Learning book

* Update addition with suggestion

Delete conjunction

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

@@ -441,6 +441,7 @@ Books that cover a specific programming language can be found in the [BY PROGRAM
 * [The Elements of Statistical Learning](https://web.stanford.edu/~hastie/ElemStatLearn/) - Trevor Hastie, Robert Tibshirani, and Jerome Friedman
 * [The LION Way: Machine Learning plus Intelligent Optimization](https://intelligent-optimization.org/LIONbook/lionbook_3v0.pdf) - Roberto Battiti, Mauro Brunato (PDF)
 * [The Little Book of Deep Learning](https://fleuret.org/public/lbdl.pdf) - François Fleuret (PDF)
+* [The Mathematical Engineering of Deep Learning](https://deeplearningmath.org) - Benoit Liquet, Sarat Moka, Yoni Nazarathy
 * [The Mechanics of Machine Learning](https://mlbook.explained.ai) - Terence Parr, Jeremy Howard
 * [The Python Game Book](https://web.archive.org/web/20210308080726/https://thepythongamebook.com/en%3Astart) - Horst Jens *(:card_file_box: archived)*
 * [Top 10 Machine Learning Algorithms Every Engineer Should Know](https://www.dezyre.com/article/top-10-machine-learning-algorithms/202) - Binny Mathews, Omair Aasim