describe how to use Redirect's options prop

[odjhey]

Docs for this change https://github.com/redwoodjs/redwood/pull/4704.

@Tobbe , please check, i'm not confident with my english esp for docs related usages ( ｡･ω･｡) so feel free to make big changes.

Thanks and good day!

[odjhey]

thanks @Tobbe!