Create / config an Action that validates the expected structure of an NR1 application

[tangollama]

There are a number of commands and configurations that we're recommending / enforcing internally w/r/t to NR1 apps w/in New Relic. We want to be sure we're validating that these configurations exist so that we have the capability to execute things like linting commands further downstream in the process.

• [x] README.md
• [x] .prettierrc.js
• [x] .eslintrc.js
• [x] .gitignore
• [x] .releaserc
• [x] package.json
• [x] LICENSE
• [x] THIRD_PARTY_NOTICES.md

In addition, the package.json should contain the following commands:

• [x] scripts.eslint-check
• [x] scripts.eslint-fix

See our current, standard circleci config as a pattern.

[jbeveland27]

Files-present-action addresses all these requirements.