[Feature] Add I2p Crowdfunding Goal

**Description**: I noticed ZeroNet has a bunch of crowdfunding like goals for adding features like TOR. My request is to add one for adding I2p support.

_I don't want to be_ that person who just wants his feature added without recognizing the lots of things needed to get done but, I2p has been a popular request for a while and I think everybody can agree is greatly needed.

Plus any fundraising overflow can help raise fund other things too!

https://zeronet.io/docs/help_zeronet/donate/