Git a look under the hood.
Install MiKTeX or another LaTeX compiler which uses pdflatex for execution.
Make build.sh an executable with chmod +x ./build.sh.
Run ./build.sh for a 16:9 presentation.
When both versions (16:9 and 4:3) are needed the parameter 43 can be added ./build.sh 43.
Open the pdf with your PDF viewer e.g. firefox ./bin/169/GitInternals.pdf and firefox ./bin/43/GitInternals.pdf.
The images can be viewed in the images directory. Where a *.drawio file is provided it can be viewed and edited at Draw.io.
The images are exported by toggling the different layers of the drawing. Or when appropriate the images are exported by each tab of the Draw.io session.