Add custom code to the init.zsh file.

Custom functions can go in the functions subdirectory, where the name of the file is the name of the function. These functions will be lazy loaded.

For example, this function:

foo() {
 print bar
}

will become a lazy loaded function if created as a file named foo in the functions subdirectory, containing:

print bar

There is a special kind of function that can also be added to the functions subdirectory: completion definitions that will be loaded by compinit. These must have file names starting with _.

Having an init.zsh file or functions inside the functions subdirectory are both optional. You can have one, the other, or both.