optFunctionTo results in a function which needs to be called when using
the option value. This is needed when the argument is not known when
building types (such as with pkgs). When the args are known (for
example, moduleArgs), this leads to more complex code than just calling
the function and resulting in the target type. optCallWith does the
latter.
Instead of having to call the configuration generation functions, the
params can just be set, and the functions will be called automatically
with additional useful settings automatically set.
The set of args passed to modules is useful for more than just
autoloading. This renames it appropriately and makes it available
through pkgs arguments as well.
This allows a configuration to be set as a function that will be passed
autoloadArgs. This is useful when each configuration is in its own file
when autoloading.
