dashes: should ignore - in link

[azu]

✓ @textlint-rule/textlint-rule-preset-google/google-dashes: Use "—"(em dash) instead of " - "(hyphen)
https://developers.google.com/style/dashes
/Users/azu/.ghq/github.com/almin/almin/docs/tips/nesting-usecase.md:88:4
           v
    87. - [IncludeAndExtend](https://martinfowler.com/bliki/IncludeAndExtend.html "IncludeAndExtend")
    88. - [uml - What's is the difference between include and extend in use case diagram? - Stack Overflow](https://stackoverflow.com/questions/1696927/whats-is-the-difference-between-include-and-extend-in-use-case-diagram "uml - What's is the difference between include and extend in use case diagram? - Stack Overflow")
    89.
           ^

This is valid pattern.

[azu]

We will ignore Str node on child of link node.