Adds more instructions for using and running docker

[skrawcz]

I added a prebuilt image to docker hub and instructions to fetch that.

Otherwise added instructions so that people know how to run the other examples.

Note: we don't auto create environments for all the example because some have other requirements like in the data_quality folders, e.g. requirements-ray.txt which aren't auto generated. So users will have to figure that out themselves.

Changes

• readme text in examples folder.

Testing

1. N/A

Notes

Checklist

• PR has an informative and human-readable title (this will be pulled into the release notes)
• Changes are limited to a single goal (no scope creep)
• Code can be automatically merged (no conflicts)
• Code passed the pre-commit check & code is left cleaner/nicer than when first encountered.
• Passes all existing automated tests
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged / future TODOs are captured in comments
• Project documentation has been updated if adding/changing functionality.
• Reviewers requested with the Reviewers tool ➡️

Testing checklist

Python - local testing

• python 3.6
• python 3.7

[elijahbenizzy]

LGTM