Add organizations page

[lukefretwell]

Is your feature request related to a problem? Please describe.

There's no way to see a list of organizations we're monitoring.

Describe the solution you'd like

Would be great to have a page with a full listing of all the organizations we're monitoring. This would show breadth, let folks filter in a different way and be good SEO.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context

A significant percentage of the list of domains in the current monitoring list are either offline or are redirects to another domain. Seems like we could display this information on that page like:

Domain	Status
911.gov	monitoring
atvsafety.gov	redirect to cpsc.gov
budget.gov	offline