Create workflow to release alpha version on PR Merge

A workflow that will run and release an alpha version each time a PR is merged into main. Don't know how f-droid handles that, but we can refer some apps on fdroid.

Version must be upgraded automatically and changelog has to be added in fastlane directory.

There is no way to release alpha or any other versions on fdroid. Since F-droid doesn't support alpha/beta/prod.