Create admin interface for Cleveland based companies

[schneidmaster]

Related to #4 and depends on #5 -- instead of having the companies hardcoded in HTML, it would be great to have an admin interface where we could create the companies with a form.

We'd probably need the following:

• Company model with name, description, address, website, published attributes (maybe more? that's what comes to mind for me). It should also have a logo file attachment attribute with ActiveStorage. I can configure S3 to store the images from ActiveStorage in production once the rest is ready.
• Standard CRUD for companies in admin -- list view, show view, new/edit forms, destroy action

[jonknapp]

@joelbyler brought up on today's Ruby Tuesday call that this could potentially open github issues for us when a request comes through.