All the lecture notes are in the Markdown syntax and compiled to HTML (in particular, reveal.js) using pandoc.
For example, l00-intro.txt is a Markdown source file and l00-intro.html is the resulting HTML slides.
It is not recommended to convert the slides to PDF,
as the .txt or .html notes should work better.
However, if you do prefer .pdf files,
use Google Chrome, append ?print-pdf to the URL of HTML slides,
such as l00-intro.html?print-pdf,
and set “Destination” to “Save as PDF”. See the
PDF export instructions from reveal.js
for details.