Ok so I have installed botania (version R1.9 339) and I have put GoG in my mods folder as there is no addons folder for botania and I start up minecraft, get on, create a new world and garden of glass isn't an option, then I check my mods through minecraft and GoG isn't in the list, I check my minecraft folder and it is there. I'm not sure what's going on, feel free to correct me if I'm doing something wrong.