Adds first pass example using movie example from metaflow

[skrawcz]

Goal of this PR is to provide more extensive examples.

Inspiration is from:
https://github.com/Netflix/metaflow/blob/master/metaflow/tutorials/01-playlist/playlist.py

Two interesting things to note here:

1. We could have the driver do the loading of the CSV, or we could have a function to do it.
2. Filter operations are easiest to happen in the driver I think. Not to say you can't do it,
   we'd just need better logic around creating the dataframe, and not trying to combine series
   with various index lengths. Hmm.

Additions

• Examples

Removals

• N/A

Changes

• N/A

Testing

1. The example works. Tested locally.

Todos

• [] add more examples and see if this makes sense.

Checklist

• PR has an informative and human-readable title
• Changes are limited to a single goal (no scope creep)
• Code can be automatically merged (no conflicts)
• Code follows the standards laid out in the dev standards.
• 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 (including the "Unreleased" section of the CHANGELOG)
• Reviewers requested with the Reviewers tool ➡️

Testing checklist

Python

• python 3.6
• python 3.7