doc: simplify urlObject.hash description

It's an octothorp, but no one knows what that is either so let's just
show the character in the sentence and be done with it.

PR-URL: nodejs#22326
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Bryan English <bryan@bryanenglish.com>

doc/api/url.md

@@ -929,7 +929,7 @@ For example: `'user:pass'`.
 #### urlObject.hash
 
 The `hash` property consists of the "fragment" portion of the URL including
-the leading ASCII hash (`#`) character.
+the leading `#` character.
 
 For example: `'#hash'`.