Publish a GitHub Action for Tartufo on the GitHub Action Marketplace

[mxhenry-godaddy]

Feature Request

Is your feature request related to a problem? Please describe.

n/a

Describe the solution you'd like

Publish a GitHub Action for Tartufo on the GitHub Action Marketplace

Describe alternatives you've considered

n/a

Teachability, Documentation, Adoption, Migration Strategy

With the adoption of GitHub Actions by GitHub users this would provide a simple way for them to consume the tool without having to set up anything special in their codebase

[c-jcarlsen-godaddy]

The new scan-local option would also allow a tartufo github action to run without providing it a PAT and just use the built in shallow clone in GitHub Actions default instead (actions/checkout)