fix(docs): fix broken indexed link from Google search

[sfirke]

https://superset.apache.org/docs/contributing/translations/ is the first Kagi search hit for "superset translations contribute", but it's broken. Here's a redirect.

[sfirke]

It looks to me this is failing b/c I am redirecting to a heading within the howtos page? I'll remove it, that's a bummer if that's the case though.

[rusackas]

Closing/reopening to kick-start CI.