Pull Request #12 from Github: Fix Translation

A "Leitweg-ID" is only used for public clients. The specification at https://xeinkauf.de/app/uploads/2023/02/231-XRechnung-2023-02-03.pdf specifies that the Buyer Reference can be a "Leitweg-ID" but doesn't necessarily have to be one and can also be a "Käuferreferenz" (Buyer Referernce) of any other kind.