This is a sophisticated book writing platform. Whenever you push files to the main branch on GitHub, the system automatically compiles them and uploads the resulting PDF file to the release page.
The resulting PDF file is named in the following format: "sample-yyyymmdd-i", where "yyyymmdd" represents the date, and "i" is a sequential number within that date.
To give it a try, you can fork this project, make modifications to the included LaTeX file, and push your changes.