docs/recording/: add entry about how F-Droid handles this

attestations can be shared in a separate sig-repo. For a detailed overview of

the conventions so far see the separate

[JVM page]({{ "/docs/jvm/" | relative_url }}).

### [F-Droid](/who/projects/#F-Droid)

F-Droid follows how the Android, Gradle, [Maven](https://github.com/DataDog/reproducible-central/blob/master/BUILDSPEC.md) and JVM ecosystems work for build dependencies.  Build dependencies are declared with the full package name and version.  Then F-Droid's [build metadata](https://f-droid.org/docs/Build_Metadata_Reference/) includes fields to declare how the build environment should be set up before the build is run.  [Any specific requirement](https://gitlab.com/fdroid/wiki/-/wikis/Recording-the-build-environment) needed to reproduce the APK should be declared in these build tools.