Create or modify Fastly service for crossword page entry point

[SiAdcock]

We need a service in Fastly to route to the new frontend endpoint for the crossword page in the Guardian Digital Editions app.

As part of this ticket, we should decide on a subdomain for this page, or rule out using a subdomain.

The advantage of hosting on a subdomain is that we can apply cookie-scrubbing functionality (example), that ensures cookies on *.theguardian.com are not accessible from within the app. This reduces exposure to security risk and reduces the need to ask the user for cookie consent.

Options:

• add crosswords.theguardian.com as an additional domain to the main dotcom Fastly service
• create a new Fastly service for crosswords.theguardian.com