title: How do i add a model with unique fields per entry, in rails?
body: <p>I am trying to setup an application that has a Hero model
  and an Ability model, each hero has many Abilities.</p>
  
  <p>Each Ability entry has some common fields, such as name, description, damage, range, duration. And so on.</p>
  
  <p>But each entry should be able to have fields that are unique to that entry alone
  for example, one single ability will have the fields: tether_duration and break_distance</p>
  
  <p>How would i setup my models to be able to allow for this? Because i can't get my head around it right now</p>