World builder now loads the tile map json and usese the keys to figure out how to randomize the floor configurations.

config.hpp

@@ -12,6 +12,8 @@ struct Config {
   Config(nlohmann::json config, std::string src_path)
     : $config(config), $src_path(src_path) {}
 
+  std::vector<std::string> keys();
+
   nlohmann::json &operator[](const std::string &key);
 
   std::wstring wstring(const std::string main_key);