Offline Usage/Running Locally?

[NightfireKalos]

I'm a stranger to code in general, so maybe I'm just not doing things right, but I'd like to run the program on my own computer with the code from this. I did download the code .ZIP file, but I haven't figured out how to set it up yet. I love the program, but the option would be very appreciated as I wouldn't have to go back and forth plus require a connection for times when I play Minecraft offline.

I see that the code downloadable from here is only the "public part" - does it mean that there is another essential part of it that cannot be posted publicly?

If it's possible to run the program on my own computer, I'd like to know how. Thanks!