Enable YAML linting GitHub Actions Workflow

[atc0005]

• https://github.com/marketplace/actions/yaml-file-linter
• https://github.com/jacobtomlinson/gha-lint-yaml

Assuming that this workflow:

• runs frequently
• in a different workflow file from all others
• rarely changes

this should help me catch errors in other Workflow files and any future config files that I add. Additionally, this can be expanded for use (presumably?) in Ansible repos that I work with.