ACON::Application#add method requires instances of each command to be provided.
ACON::Loader::Interface provides a way to lazily instantiate only the command(s) being called,
which can be more performant since not every command needs instantiated.
Direct including types
#get(name : String) : ACON::Command#
#has?(name : String) : Bool#
self has a command with the provided name, otherwise