Customizing the friendliness/aggressiveness of mobs

[nttldnknwn]

Please consider adding a feature responsible for the aggressiveness of mobs towards the player.

Something like the setting currently available for the cow:

      cow:
        naturally-aggressive-to-players:
          chance: 0.0

Would like to be able to customize the friendliness/aggressiveness of all mobs.

Thanks!