Stop previews from redirecting to production site.

[johnnymatthews]

If you click on a preview link within a PR, like update-clarify-assertion-flo.docs-czv.pages.dev/ for example, you'll get redirected to the production docs site docs.shinzo.network. The workaround currently is to go to a non-root page, say /reference/architecture/, and tack on the preview URL to the start of it, so https://update-clarify-assertion-flo.docs-czv.pages.dev/reference/architecture/. Kinda annoying.

Task

• Figure out what's causing the redirects in the preview branches.
• Stop redirecting to the production site when visiting / or /understand/what-is-shinzo/.