Proposal: Change the interface for action groups to include store name

[JRJurman]

Summary

The current interface for passing action groups is a key: action group, where the key is the store name. It might be more clear instead to have a dedicated key for action groups that is intelligently used

Current

engine.addActions({
  storeName: {
    init: () => 5
  }
})

Proposal

engine.addActions([
  {
    store: 'storeName',
    init: () => 5
  }
])

While this may seem trivial here, it means that action files (which are usually separate) can also dictate the storeName, rather than having those exclusively defined when the engine adds them.