Add examples that are not about simply dispatching #18

Right now all examples take the same number of arguments, return the same thing, etc. We should show some examples of:

• Variants that take a different number of arguments from one another
• Variants which return different things
• A variant that suppresses a specific error maybe?
• Variants for maintaining backwards compatibility
• Caching and non-caching versions of a function
• Asynchronous and blocking versions of a function