docs: def update(self, skill=None, author=None):
          """Update all downloaded skills or one specified skill."""
          if skill is None:
              return self.update_all()
          else:
              if isinstance(skill, str):
                  skill = self.find_skill(skill, author)
              entry = get_skill_entry(skill.name, self.skills_data)
              if entry:
                  entry['beta'] = skill.is_beta
              if skill.update():
                  # On successful update update the update value
                  if entry:
                      entry['updated'] = time.time()