README

<!-- ~ SPDX-FileCopyrightText: 2023 Álvaro Brey <[email protected]> ~ SPDX-License-Identifier: AGPL-3.0-or-later OR GPL-2.0-only -->

This src/ directory is only here for F-Droid, as it doesn't pick up per-flavor metadata in the app/ subdir. Tracking issue: https://gitlab.com/fdroid/fdroidserver/-/issues/829