Write a user manual for Lino Cosi so that a motivated newbie user can make a tour without needing support. Use the [url cosi-demo.lino-framework.org/ official demo] and update it to fix problems that are disturbing for a first tour. Focus on managing products and writing offers, especially also offers with longer explanations. Ask Luc for samples. Optimize the default.weasy.html template for VatProductInvoice.