`/docs/` redirect seeded from all redirect.yml files.

[Mpdreamz]

We already collect all redirects as part of #1207

We need to ensure we can seed a cloudfront keyvaluestore during our production/staging deploys and create a lambda too query it and facilitate the redirects.

• I tink we need isolated instances for preview, staging, production.
• The lambda should do soft redirects in preview and staging and hard redirects in production.