Allow choice between GitHub releases

This PR allows users to choose which asset to download in the event that there are multiple compiled assets available (as seen [here](https://github.com/rbray89/ActiveTextureManagement/releases)) asking them which to use when adding/updating instead of simply using the first.
If you're not attached to the set, and are assuming that we will have no duplicate entries, we can instead use a LinkedList, and use:
```
assets.get(0);
```