Add links for Portainer and Supabase to the Dashboard

[humphd]

We've got two new admin apps that we need to access:

1. Portainer
   • Staging = https://dev.portainer.telescope.cdot.systems/
   • Production = https://portainer.telescope.cdot.systems/
2. Supabase
   • Staging = https://dev.supabase.telescope.cdot.systems
   • Production = https://dev.supabase.telescope.cdot.systems

Let's add these links to the sidebar of the Dashboard, so they are easier to find.

NOTE: in order to access these, you have to be a member of the 'Telescope Admins' group on GitHub. I can add whoever needs it (everyone that's maintaining things should already have it).

[joelazwar]

Gonna push a quick PR for this, just one thing, the links for Supabase are the same for staging and prod. Are we using the same Supabase instance for both staging and production?