Add new subcategories for projekte

Instruction on how to add more items:

1. Add category here https://prnt.sc/8fWefsiCq6Is

2. Apply the created category to any page https://prnt.sc/FdSDPbPRRq2J

3. Open to edit page, scroll below, and select the existing subcategory here for the page https://prnt.sc/7XvrfE3tkvG5 (only subcategory that is used for pages showing on the website, empty subcategories aren’t shown)