Ideally, the Wikipedia bag is also mentioned in the confirmation e-mail that is sent after a membership application. While at it, we should remove the double whitespace in the salutation.

Acceptance Criteria

• The sentence "Sie bekommen zunächst ein Willkommensschreiben von uns." is replaced by "Sie erhalten zunächst unser Willkommenspaket per Post."
• If a user chose to receive the bag, the sentence mentions the bag: "Sie erhalten zunächst unser Willkommenspaket mit dem Wikipedia-Stoffbeutel per Post."
• The double whitespace in the salutation is reduced to a single whitespace (Lieber Herr Zuse).