Hook for setting initial session state

[elliott-with-the-longest-name-on-github]

It would be super cool to have a hook in handleSession for setting the initial session state:

const generateInitialState = () => {
  return {
    something: 'default'
  }
}

export const handle = handleSession({ 
  init: generateInitialState
});

This would enable us to make sure the shape of the object we're storing in sessiondata is always what we expect (and not "undefined")

[pixelmund]

Hey you can now set the initial session state with version 3.3.0

export const handle = handleSession({
    init: (event) => ({
        views: 0
    })
});

[elliott-with-the-longest-name-on-github]

❤️