Document fall back to CloudFront as a manual process
Document fall back to CloudFront as a manual process

Deploying these changes using Jenkins and Terraform is too slow and
unreliable to do during an incident.

To be honest, I think this would be better as a shell script. I'll raise
this as a PR to get people's opinions.

alphagov/govuk-developer-docs,alphagov/govuk-developer-docs,alphagov/govuk-developer-docs,alphagov/govuk-developer-docs