Move talks into year-specific sub-directory

talks/2020/tensorflow/img/cg/cg1.png

talks/2020/tensorflow/img/copyright_infringement.png

talks/2020/tensorflow/img/demos/.gitkeep

talks/2020/tensorflow/img/demos/nothing_here

talks/2020/tensorflow/img/fchollet_popularity_2017.jpg

talks/2020/tensorflow/img/how_big_is_your_data.png

talks/2020/tensorflow/img/model_zoo.png

talks/2020/tensorflow/img/multiple_devices.png

talks/2020/tensorflow/img/so_hot_right_now.jpg

talks/2020/tensorflow/img/what_leo_needs.png

talks/2020/tensorflow/oiwi_pytreat_tensorflow_notes.ipynb

talks/2020/virtual_intro/data/2d_array.txt

talks/2020/virtual_intro/data/comma_separated.txt

talks/2020/virtual_intro/data/file.txt

talks/2020/virtual_intro/data/space_separated.txt

talks/2020/virtual_intro/intro.ipynb

talks/2020/virtual_intro/intro.md