It wasn’t opendesk unfortunately. I saw it maybe a year ago and I just remembered it recently.
I think it was run by a nonprofit (or maybe it was some kind of company, idk) that I think both did planning for communities officially and provided the resources to do it on your own. Their wiki had multiple different sections, such as furniture, bus stops, beergardens, farmers markets, and more.
I want to say it got started in Portland but that could be a fever dream :/
Holy shit you found it! Thank you so much! I swear I searched every combination of beer garden but I couldn’t find it myself!