wordpad: update Polish translation

[Jacek Caban]

Hi Mikołaj,

Mikołaj Zalewski wrote:
> +
> +STRINGTABLE DISCARDABLE
> +BEGIN
> +    STRING_RICHTEXT_FILES_RTF,  "Tekst sformatowany - RTF (*.rtf)"
> +    STRING_TEXT_FILES_TXT,      "Document tekstowy (*.txt)"
This is a typo, it should be "Dokument".

Jacek