docs: def load_installed_plugins():
          """Search and load every installed plugin through entry points."""
          providers = {}
          checkers = {}
          for entry_point in pkg_resources.iter_entry_points(group='archan'):
              obj = entry_point.load()
              if issubclass(obj, Provider):
                  providers[entry_point.name] = obj
              elif issubclass(obj, Checker):
                  checkers[entry_point.name] = obj
          return collections.namedtuple(
              'Plugins', 'providers checkers')(
                  providers=providers,
                  checkers=checkers)