Chore(#68): Add development guidelines

[andybeet]

Justification

For better collaboration suite of files added. Pull request templates, workflow formating checks and contributing guidelines. The repo also needed formatting to air standards.

Fixes #68

Types of changes

What types of changes does this pull request introduce? Put an x in the boxes that apply.
This will inform the new release number.

• Fix (non-breaking change which fixes a bug)
• Feature (non-breaking change which adds or changes functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Other change (if none of the other choices apply)

Reviewer instructions

Take a look at the CONTRIBUTING guidelines and the CODE_OF_CONDUCT in case we need to modify them for this repo. The ymls are directly from Rstudio folks as is the advice of toml use. See below for notes on Air and its use

Formatting

This repo contains an air.toml file that automatically formats code to a set of standards.
It is preferred that contributors and reviewers install the Air formatting tool.
Code submitted in this pull request will be automatically checked for correct formatting.