Add invoice PDF generation

[jgarte]

Could we add support for generating invoice PDFs through Kimai’s API?

Would this first require an endpoint that accepts invoice generation options and creates the PDF server side?

[jgarte]

@kevinpapst I'd be happy to help with this if you think it is a good idea.

[kevinpapst]

@jgarte We need an API endpoint first and I am in the middle of restructuring, so I would give that a try first and then come back to you to integrate it here.

[jgarte]

@kevinpapst By restructuring, do you mean that you are reorganizing the invoice code so it can be exposed through the API, or something else?

My main use case is that I'd like to generate a new invoice from options such as customer, dates, and possibly a custom template.