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.
In lua, you can do `for key, value in pairs(table)` or `for value in (...)`. It's very different for different languages evidently.