Add a mention of Ryan/Freehive to Odin/Jólnir merch

It'd be a nice gesture to mention that they designed the wallpaper in the descriptions of these items; since Printful doesn't have a way to edit/append to descriptions, we could just add something to the template like:

```pseudocode
if (product.name includes "Odin" or "Jólnir") {
print ("Odin and Jólnir wallpapers were designed for elementary by Freehive.")
}
```