Add latest APK build to releases

[leeoocca]

The Play Store page is unfortunately down: https://play.google.com/store/apps/details?id=com.paulvarry.intra42

But the app still works by downloading the APK from the Releases section of this repo: https://github.com/pvarry/intra42/releases/

Unfortunately the latest available version is v0.6.2, while the latest version is v0.12.7 (https://github.com/pvarry/intra42/commit/4b32462dd884d41f8d92b4eff75dc12b77743f7e).

Would it be possible to add the latest release build to the releases tab?

The app is still great! Just a pity not to enjoy all the hard work behind it :/