Major rework of access to the iRacing API.

A bug was noticed where my YAML wasn't correctly being mapped. I've replaced the nested key access with a more sensible top-level key access, massively cleaning up the codebase.
Added a benchmarker to see how fast I can read from memory - results: really fast.

May have to look into running it long term whilst playing to see effect etc.
Updated README
Version bump 1.1