doc: simplify urlObject.hash text

Remove "consists of" in favor of "is". Use "fragment identifier" instead
of "fragment" and remove quotes.

PR-URL: https://github.com/nodejs/node/pull/22326


Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Bryan English <bryan@bryanenglish.com>