Add Pyramid chart to County Compare App

[banjtheman]

What is the Task

Create a Pyramid Chart for the County Compare app
https://altair-viz.github.io/gallery/us_population_pyramid_over_time.html

Why do we want to do this

To visualize differences between two counties

How can I get started?

1. Remove current code in the view
   https://github.com/banjtheman/defundthepolice/blob/main/apps/county_compare/views.py#L29-L56

2. Replace with code that renders a pyramid chart for the selected counties
   Here is example code
   https://altair-viz.github.io/gallery/us_population_pyramid_over_time.html

x-axis should be percent
y-axis should be item

• Leave any questions in comments,
• If you want to work on the issue go ahead no need to ask

Definition of Done

Pyramid chart shows in the County Compare App