Update setup to create environment and install dependencies

[miltondp]

This is a preliminary set of changes that use conda to setup the virtual environment. I was able to compile the slides in Ubuntu (some of them, like lecture12, failed to create a PDF because of missing characters).

I didn't test all the code though. For example, here I'm including pytorch 2 and the original requirements.txt files has version 1.4, so it's likely to break.