Bug in Design redirections - add `-/`

Problem to solve

Right now older URLs to Designs are still being used in issue descriptions and comments. This is causing our users to experience broken links.

Old format vs new - addition of -/

https://gitlab.com/gitlab-org/gitlab/issues/22702/designs/Wiki%20editing.png

https://gitlab.com/gitlab-org/gitlab/-/issues/22702/designs/Wiki%20editing.png

Further details

Proposal

• Create 301 redirects to handle the older URLs

Documentation

• Check docs to make sure there are no updates around the URL

Availability & Testing

Links / references

Thanks for filing @timhey