Markdown/YAML Linters

[devlinjunker]

Describe the Improvement:
Should provide examples of using linters, so we can update style guide

• Markdown: https://github.com/markdownlint/markdownlint
• YAML: https://github.com/adrienverge/yamllint

See also devlinjunker/template.github.semver#51

Benefits:

• Ensure that Github Actions do not contain syntax errors

Drawbacks:
Slows build/release process

How to Compare:
Should see reduced number of errors in github action files when merged

[devlinjunker]

Hmm.. both of these require npm and package.json....

• https://github.com/igorshubovych/markdownlint-cli
• https://github.com/rasshofer/yaml-lint

Maybe these should be in a template npm repo?