Remove jQuery from manuals-frontend
Remove jQuery from manuals-frontend

- only jQuery was this document.ready equivalent for primaryLinks
- replacing this is possible but slightly complicated by browser compatibility issues
- so maybe we could remove it entirely
- we've already removed document.ready successfully elsewhere on GOV.UK without a direct replacement, and testing this here it seems to work as well
- primaryLinks is still initialised and run successfully

alphagov/manuals-frontend,alphagov/manuals-frontend,alphagov/manuals-frontend,alphagov/manuals-frontend