Add support for Wildcards

, in the same vein as wildcard plugins work elsewhere i.e. you would write something like $object in your prompt and it would grab the token from a text file called object.txt randomly and that file would include a very long list of general "objects" but you could also have more specific wildcards such as $animal or $cat (would list only types of cats). This is usually done for things like $food, $location, etc etc etc. Would be great to have this as a way to randomize and spice up prompts or even the option to wildcard an entire prompt.