Add example to README that does not use pattern matching

[malandis]

We default the README example to demonstrate pattern matching on the synchronous client. Currently there are four examples: two that show pattern matching (only supported in python >= 3.10) and two that do not; then two that demonstrate the asynchronous client and two that demonstrate the synchronous one.

At a minimum the README should display the pattern matching and non pattern matching on the synchronous client. Add the non-pattern matching example to the README.