request tax exemption status for dCA with cantonal authorities

- it's unlikely that we get it, but it would allow us to 
   - get google gsuite for free
   - get free google ads media spend (#71 )
- https://www.vitaminb.ch/uploads/media/default/1110/steuerbefreiung2019.pdf
- https://www.vitaminb.ch/vereinsthemen/finanzen/steuern