Include examples in the documentation

[ghickman]

When arriving at the documentation, or readme, it isn't immediately clear how to use this library in my own code. A worked example would do wonders on the front page for both bits of documentation.

I suspect you would only need to showcase a handful of the functions too, the 80% ones if you will, and leave the more edge-case ones, eg transaction_if_not_already, to the API docs where their nuances can be fully explained.