Add links to Youtube videos

Author: gjbex

README.md

@@ -21,3 +21,17 @@ For information on the training, see the website
 1. [Contributing](CONTRIBUTING.md): information on how to contribute to this
    repository.
 1. docs: directory containing the website for this repository.
+
+
+## Video sessions
+
+Video recordings of this training are available on YouTube.
+
+1. [Introduction](https://youtu.be/QIZ0-oHwMaI) (25 minutes)
+1. [scikit-learn: data pipelines and regression](https://youtu.be/sy4U9VteP8Q) (28 minutes)
+1. [scikit-learn: classification and clustering](https://youtu.be/acXmk4Bx8pI) (12 minutes)
+1. [keras: introduction to neural networks](https://youtu.be/-CO0Y8wzYeI) (13 minutes)
+1. [keras: multilayer perceptrons for digit recognition](https://youtu.be/nAixWMYgzdo) (34 minutes)
+1. [keras: convolutional neural networks for digit recognition] (19 minutes)
+1. [keras: recurrent neural networks for sentiment classification](https://youtu.be/TkafYl9APpM) (26 minutes)
+1. [