Eleventy Action to build and deploy to GitHub Pages

The credit goes to TartanLlama, but when there have not been any updates, and a new website calls for an updated action.

This has been updated to:

• Node 18
• runs-on: ubuntu-latest
• Updated Docker file to use npx @11ty/eleventy instead of the older eleventy
• Updated Readme.md with the suggestions on proper args pass-through.