Okay to remove mention of mystery @ and ~ operators?

Hello

This page says that the `@` and `~` operators on various types can be
accelerated by a GiST index.

https://www.postgresql.org/docs/current/gist-builtin-opclasses.html

These operators have been listed in the file since it was created in 2014,
but if they exist then I don't know how to use them or what they do.

Code examples, for clarity:

> select box '(0,0),(1, 1)' ~ box '(2,2),(3,3)';
operator does not exist: box ~ box

> select box '(0,0),(1, 1)' @ box '(2,2),(3,3)';
operator does not exist: box @ box

If they're a typo or some removed thing then I'd like to remove them from
the page. This email is me asking to find out if I'm wrong about that
before I try to submit a patch (also very happy for someone with a
committer bit to just fix this).

Cheers,
Col