Match parens for hidden files parenthetical

Co-authored-by: Josh Soref <2119212+jsoref@users.noreply.github.com>

dir.rb

@@ -230,7 +230,7 @@ class << File
   #   <code>\*c*</code>:: Matches all files that have <code>c</code> in them
   #                       (including at the beginning or end).
   #
-  #   To match hidden files (that start with a <code>.</code> set the
+  #   To match hidden files (that start with a <code>.</code>) set the
   #   File::FNM_DOTMATCH flag.
   #
   # <code>**</code>::