Clarify non-alphanumeric characters in name field

The specification and reference implementation differ in how they handle non-alphanumeric characters.

The main specification page writes:

May only contain unicode lowercase alphanumeric characters (a-z, 0-9) and hyphens (-)

While the reference implementation provides:

Chinese characters are allowed in skill names.

There is an open PR to resolve the issue by supporting all unicode characters in the spec, but there has been no comment since the PR was created in Apr 29, 2026.

Claude supports skills with non-alphanumeric characters, while recent discussion seems to favor alphanumeric characters only.

Would it be possible to clarify one way or the other?

Thanks!