Load modules-related configuration listened in modules section
     Before loading:
      "modules": {
      "mal": "myanimelist.json",
      "ann": "animenewsnetwork.json"
     }
     After loading:
       "modules": {
        "mal": {
         ....
        },
        "ann": {
         ....
        }
      }

def _load_modules(self):
    """
    Load modules-related configuration listened in modules section
     Before loading:
      "modules": {
      "mal": "myanimelist.json",
      "ann": "animenewsnetwork.json"
     }
     After loading:
       "modules": {
        "mal": {
         ....
        },
        "ann": {
         ....
        }
      }
    """
    if self.exists("modules"):
      for item in self._json["modules"]:
        try:
          json_data = json.loads(self._load_from_configs(self._json["modules"][item]))
          self._json["modules"][item] = json_data
        except Exception as err:
          raise FileNotFoundError("Couldn't load module {} configuration from {}: {}".format(item, self._json["modules"][item], err))