The main entry point to Jit is via the Bash script ./jit in the root directory.
New Jit commands are stored in the cmd/ directory with a .sh extension. So, for example, when you call
jit foo bar baz
Jit will look for the script cmd/foo.sh, and if found, it will run this script with the arguments bar baz.
If the script is not found, Jit will call
git foo bar baz