Adds coding guidelines to contributors doc (#257)
Adds coding guidelines to contributors doc (#257)

* Details on how to run markdown linter
* Link to Ansible Style Guide
* Multi-line YAML
* Correct use of lists
tima/lightbulb,ansible/lightbulb,tima/lightbulb,ansible/lightbulb,ansible/lightbulb,ansible/lightbulb,tima/lightbulb