Nothing makes me happier than to download full documentation in pdf format; ..I'm a very cheap date.
I'm reading a book on React Native at the moment, and it speaks glowingly about the benefits of using Expo for rapid development. I wanted to learn more, but quickly hit a wall: the documentation is only available on the website.. no pdf.
I took a brief detour.. and wrote some scripts to convert the docs from markdown (obtained from this repo) to various ebook formats: pdf, epub, and mobi.
The scripts are GPLv2.