achievements and daily tasks feature#23

a new command: .achievements, where there are goals for users to complete to gain prizes. there would be some achievements there for people to get to, and once you complete one, you would get a prize. for example, one goal could be “vote 20 times” and if you voted 20 times you would get, for example, 2 stars. once you voted 20 times, the goal would transform into “vote 50 times” and so on. another goal example would be “get 5 activity classes”, or something like that.