Better / Consistent Formatting

## What is your idea?

Add some means to have consistent formatting across the codebase. See comment https://github.com/aws/event-ruler/pull/39/files#r967886681 for some early thoughts.

## Would you be willing to make the change?

Maybe

Start by reading the early formatting discussion in the comment linked from the issue and inspect the repository to identify how formatting is currently handled. Determine the intended formatting approach before changing files. Done means the codebase follows one consistent formatting style, with the chosen approach documented or enforced.

Written by the indexing model from the issue text.