Update free-programming-books-langs.md (#6922)

Add Tiny Python Projects for Python Learning，this book is free

books/free-programming-books-langs.md

@@ -1977,6 +1977,7 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 * [Think Python 2nd Edition](https://greenteapress.com/wp/think-python-2e/) - Allen B. Downey (3.x) (HTML, PDF)
   * [Think Python First Edition](https://greenteapress.com/wp/think-python/) - Allen B. Downey (2.x) (HTML, PDF)
 * [Tiny Python 3.6 Notebook](https://github.com/mattharrison/Tiny-Python-3.6-Notebook) - Matt Harrison (3.6)
+* [Tiny Python Projects](http://tinypythonprojects.com/Tiny_Python_Projects.pdf) - Ken Youens-Clark(PDF)
 * [Web2py: Complete Reference Manual, 6th Edition (pre-release)](http://web2py.com/book) (2.5 - 2.x)