Provide a ruby example scraper with headless chrome

[ianheggie-oaf]

Description

There are a number of issues relating to chrome headless scrapers. I feel providing a working example would go a long way to helping get the other scrapers working, and would be a nice addition to the documentation. Related issues include:

• Capybara with selenium fails on ruby 2.7.6 #1337
• Chrome headless scrapers appear broken #1201

Describe the solution you'd like

An example others can use when they need headless chrome

Describe alternatives you've considered

Get a real scraper working and use that as the inhouse example

Additional context

Previous buildsteps are failing:

• buildstep: Dockerfile.cedar-14 fails to build #1335
• buildstep: Dockerfile.heroku-18 fails to build #1334