Background
As part of T333144: [EPIC] Migrate DSG resources to Codex we need to redirect https://design.wikimedia.org/style-guide/ to https://doc.wikimedia.org/codex/latest/style-guide/overview.html
Acceptance criteria
- https://design.wikimedia.org/style-guide/ redirects to https://doc.wikimedia.org/codex/latest/style-guide/overview.html as permanent redirect after ~3 months post T347754: DSG: Add deprecation notice with eyes on the access stats.