Add RSS property for width

### Description

I would like to grab the image for the verse of the day and display it on Glance. I've set it up so but no matter what style I choose or whether I place the feed in a small or full column, the image is always very small width. I'd like for it to display full size when in a full column so the image is readable.

```
- type: rss
title: Verse of the day
style: horizontal-cards
limit: 1
feeds:
- url: https://feeds.feedburner.com/hl-devos-votd
```