[Feature Request] Download selected APK

### Before you submit

- [x] I have searched the issue tracker for [open](https://github.com/Droid-ify/client/issues) and [closed](https://github.com/Droid-ify/client/issues?q=is%3Aissue+is%3Aclosed) issues that are similar to the feature request I want to file, without success.
- [x] I'm not requesting app support for a specific repo — that's up to repo maintainers
- [x] I understand this might not get built (Droid-ify is maintained by a single person)

### What's the problem?

I would like to download selected APK via Droidify.

The only way I'm able to download APK is by pressing specific app version, which copies APK link, and then use that link in browser to download the APK.

I was trying to install specific F-Droid APK in [Shelter](https://f-droid.org/packages/net.typeblog.shelter/) app, and I was expecting, that Droidify will allow me to download the APK.

### What would help?

Add button to download APK (to standard location like Downloads configured in settings)

### Alternatives?

_No response_

### Anything else?

_No response_