Remove Gratipay/Donation option from docs.
Remove Gratipay/Donation option from docs.

They changed their policy. And wasn't making a dime anyway.

bcrochet/eve,matthieuprat/eve,elpoisterio/eve,hustlzp/eve,mcreenan/eve,yanyanqin/eve,kalbasit/eve,julianhille/eve,eduardomb/eve,stratosgear/eve,mugurrus/eve,kidaa/eve,pjs7678/eve,sebest/eve,EasonYi/eve