Multiple types for slash command options

[asportnoy]

Here's an example from my use case: my regular commands have an argument where you can specify a user (ID/mention) or string. If the option is a user, the bot will use an option saved for that user in our database. Otherwise, the string passed in will be used.

The current closest thing that's available would be to use a string type and parse out user mentions like in regular message content.