Proposal: disallow moving spec pages without corresponding path redirecting

**Is your feature request related to a problem? Please describe.**

someone links me to a doc page, suddenly 404 page missing fml

**Describe the solution you'd like**
A clear and concise description of what you want to happen.

Proposal: disallow moving spec pages without corresponding path redirecting

**Describe alternatives you've considered**
using a different rollup stack

**Additional context**

Example: https://github.com/ethereum-optimism/optimism/blob/develop/specs/fault-proof.md