docs(idna): typo 'iff' with two 'f's

[extua]

Two more minor typos following on from #1052, both lines reading:

The third argument is true iff the domain name as a whole is a bidi domain name.

In the doc comment for Uts46::to_user_interface

rust-url/idna/src/uts46.rs

Line 659 in dbd5261

/// The third argument is `true` iff the domain name as a whole is a bidi domain name.

and in the comment for Uts46::process

rust-url/idna/src/uts46.rs

Line 713 in dbd5261

/// The third argument is `true` iff the domain name as a whole is a bidi domain name.