Improve app metadata, include fdroid metadata in repository

android/gradle.properties

fastlane/metadata/android/en-US/changelogs/0.txt

fastlane/metadata/android/en-US/changelogs/1.txt

fastlane/metadata/android/en-US/changelogs/2.txt

fastlane/metadata/android/en-US/full_description.txt

fastlane/metadata/android/en-US/short_description.txt

fastlane/metadata/android/en-US/title.txt

fastlane/metadata/android/fr-FR/changelogs/0.txt

fastlane/metadata/android/fr-FR/changelogs/1.txt

fastlane/metadata/android/fr-FR/changelogs/2.txt

fastlane/metadata/android/fr-FR/full_description.txt

fastlane/metadata/android/fr-FR/short_description.txt

fastlane/metadata/android/fr-FR/title.txt

fdroid_metadata.yml