xn-- TLDs in relaxed mode

[uggyuggy]

Hi,

Having a list of valid TLD is nice to limit false positives in relaxed mode.
However, the default list does contains by default only the punnycode version of the TLD but not the xn-- version of it (the IANA list contains only the xn-- version).

$ idn 联通
xn--8y0a063a
$
$ echo "test.联通" | xurls -r
test.联通
$ echo "test.xn--8y0a063a" | xurls -r
$

I would suggest having the default list composed with the 2 versions of IDN TLDs.

[mvdan]

Thanks, this makes sense. A PR is welcome - otherwise I'll get to this at some point soon.