The scrambles are extracted from https://github.com/ChristianVaughn/C2F2L
https://christianvaughn.net/C2F2L is a tremendous tool that allows you to set the difficulty of cross, and generate a scramble for you to practice cross-to-F2L transition.
However I'm used to use csTimer to record time, so I have to scramble the cube and then switch to csTimer every solve. Too lazy to do that. Therefore I extract scrambles in each difficulty level into a plain text file, then I can copy/paste it to csTimer using the "external input".