Add action for brushing

[Aarón Riveiro Vilar]

Add a new action that allows players to get paid for using the brush on suspicious sand/gravel:

  Brush:
    suspicious_sand:
      income: 1
      points: 1
      experience: 1
    suspicious_gravel:
      income: 1
      points: 1
      experience: 1

[Zrips]

57003dc