Where is the source code? Where do I open a PR to include a new icon or to fix one?

Good point, I don't think that you can include a new icon or fix one.

Source code is here https://github.com/webalys-hq/streamline-vectors/blob/main/R... and in https://www.figma.com/@05466272_9382_4.

Thank you for the feedback.

I assume you didn't write SVGs by hand for 10 years.

Publishing open source is like me publishing only the binaries of my tool and thn saying because it's free it's also 'open source'.

So, assuming you used some tool (Photoshop, Figma, etc) to export to SVG, open source would mean you publish the original files too.