Interestingly, GitHub refuses to display the PDF, saying that it's invalid: https://github.com/pjimenezmateo/curriculum-bootloader/blob/...
Some PDF parsers expect the %PDF header at the beginning of the file, which explains why it does not display on Github.
It does work on macOS Preview though. I'm scared of opening any downloaded file, by now ;)
"There was an error opening this document. The file is damaged and could not be repaired."
when trying to open with Adobe Reader.