[REQUEST] Document using `foreman` to start the app and sidekiq at once using the Procfile

[arielj]

Before we start...:

• [x] I checked the documentation and didn't find this feature
• [x] I checked to make sure that this feature has not already been requested

Branch/Commit:

Main branch.

Describe the feature:

The app currently needs 2 commands to run properly, rails s and bundle exec sidekiq. We should have a Procfile.dev file that runs the rails server and sidekiq (current Procfile doesn't work because it's intended for production)

Resources:

foreman should NOT be added as a dependency in the gemfile https://github.com/ddollar/foreman/wiki/Don%27t-Bundle-Foreman

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