Update intro_python

slides/01_intro_python.md

@@ -49,6 +49,8 @@
  * [\textcolor{violet}{scikit-learn}](https://scikit-learn.org/stable/) - machine learning library written in
    python, which makes use extensively of NumPy for high-performance
    linear algebra algorithms
+
+* [\textcolor{violet}{Tensorflow}](https://https://www.tensorflow.org/) - machine learning library with Keras as python interface 
    
 ## NumPy