Detect emails followed by a hyphen

[dyk1454683243-sudo]

Fixes #93

test() treats a comma after a valid email as punctuation, but a hyphen makes the whole match fail:

const linkify = new LinkifyIt()
linkify.test('name@example.com')   // true
linkify.test('name@example.com,')  // true
linkify.test('name@example.com-')  // false  (before this change)

After:

linkify.test('name@example.com-')                 // true
linkify.match('name@example.com-')[0].text        // 'name@example.com'

Why

- is in Unicode {P}, so the host terminator's first lookahead accepts it. The second lookahead then rejects every hyphen:

(?=$|separators|{ZPCc})(?!-|_…)

That rejection is useful for URL hosts (google.com-based should not become a link). It is the wrong rule for emails: after a completed mail host the hyphen cannot continue the address (domain labels already consume internal hyphens, and emails have no path). So name@example.com- and mid-text cases like Contact name@example.com- for details are missed entirely.

Change

Mail hosts use a slightly looser terminator: - and -- are treated like other punctuation. --- stays opt-in ({ '---': true }), so the existing user@example.com---foo default-null behavior is unchanged.

URL host termination is left as-is.

Tests

• Issue repro in test/api.test.mjs
• Fixtures in test/fixtures/links.txt: trailing - / --, mid-text, mailto:, hyphenated domains (user@my-company.com)

[puzrin]

https://github.com/markdown-it/linkify-it/blob/master/CONTRIBUTING.md