So, I am relatively new to Roll20. I created a game for my new campaign. After hours of creating maps, tokens and handouts, I bought content from the market, which I wanted to use for my campaign. While I see the tokens, there doesn't seem to be a way to add the actual adventure (maps and stuff) to my already existing game. Is it true, that I can't add that content? Do I really have to start again and chosing that content beforehand?