Create user interface for adding new URLs to be monitored

[Mr0grog]

We’ve slowly started to add pages again, and now that our workflow isn’t totally directed by what’s in Versionista, that process has become reasonably complicated, and I think I might be the only person who has a full grasp of it.

At current, this involves two main steps:

1. Add a page record to the DB:

   1. SSH into a live server via Kubernetes:

      # List available pods
      > kubectl get pods --namespace production
      # Pick an `api-` or `import-worker-` pod (basically, one of the DB pods) and log in
      > kubectl exec -it <name of pod> /bin/bash --namespace production
      
      # Open the Rails console once you are logged into the pod
      > rails c

   2. Create the page:

      > new_page = Page.create(url: 'URL OF PAGE HERE')
      # Optionally add maintainers and tags as appropriate (the `domain:` and `2l-domain`
      # tags are created automatically, so no need to add those)
      > new_page.add_tag('NAME OF TAG')
      > new_page.add_maintainer('NAME OF MAINTAINER')

2. Make sure we are actually getting that page saved on Wayback by adding it to the ia-archiver box (needs to be described in the ops repo; see Describe Wayback SPN Tools in “Manually Managed” Section web-monitoring-ops#14)

   Make sure to let @Mr0grog know if you change the config on that box, since he updates it every day or two and might accidentally overwrite your changes! (See the above issue in ops again, scream at @Mr0grog about it if you need, because he could probably use a kick in the pants.)

Anyway! It would be nice if this were fewer steps, though it is separate because it hasn’t made sense in the past for us to push every URL we monitor via SavePageNow. Maybe we could pull that config from somewhere automatically though.

It would also be nice if we could automate all that so that someone on the analyst team with admin permissions could just add a new page to monitor. I’m not sure whether the UI for that belongs in the admin panel in the -db project or somewhere in the -ui project.