I talked with @joshnabbott offline about updating the other image references so they aren't so archaic. For instance instead of

```liquid
{{ theme.image }}
```

we would use

```liquid
{{ theme.images.logo }}
```

And actually changing the settings. Since we're bumping a minor version and this doesn't have to be backward compatible fixing up those variable names to be more semantic feels appropriate.

As for the slideshow name I feel like `image_sets.slideshow` is more consistent with the way the other images will be given that change (e.g. we're not calling them `theme.images.logo_image`). I feel fairly strongly that we'll be setting an example for theme developers with this theme and I would prefer to drop the _images postfix if you guys don't have strong feelings one way or another.