doc: fix icu-small example

Running the same in the icu doc shows that for
icu-small the output is January instead of M01. Update
the example in the doc to match.

Signed-off-by: Michael Dawson <[email protected]>

PR-URL: nodejs/node#43591
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Steven R Loomis <[email protected]>
Reviewed-By: Tobias Nießen <[email protected]>

doc/api/intl.md

@@ -103,7 +103,7 @@ const spanish = new Intl.DateTimeFormat('es', { month: 'long' });
 console.log(english.format(january));
 // Prints "January"
 console.log(spanish.format(january));
-// Prints "M01" on small-icu
+// Prints either "M01" or "January" on small-icu, depending on the user’s default locale
 // Should print "enero"
 ```