doc: fix typo "director" instead of "directory"

Change fs.readdirSync() description from "Reads the contents of
the director." to "Reads the contents of the directory."

PR-URL: nodejs#37523
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Harshitha K P <harshitha014@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/fs.md

@@ -4533,7 +4533,7 @@ changes:
   * `withFileTypes` {boolean} **Default:** `false`
 * Returns: {string[]|Buffer[]|fs.Dirent[]}
 
-Reads the contents of the director.
+Reads the contents of the directory.
 
 See the POSIX readdir(3) documentation for more details.