Flatpak source initial work

src/preferences.py

@@ -26,6 +26,7 @@ from gi.repository import Adw, Gio, GLib, Gtk
 
 from src import shared
 from src.importer.sources.bottles_source import BottlesSource
+from src.importer.sources.flatpak_source import FlatpakSource
 from src.importer.sources.heroic_source import HeroicSource
 from src.importer.sources.itch_source import ItchSource
 from src.importer.sources.legendary_source import LegendarySource
@@ -124,6 +125,7 @@ class PreferencesWindow(Adw.PreferencesWindow):
         # Sources settings
         for source_class in (
             BottlesSource,
+            FlatpakSource,
             HeroicSource,
             ItchSource,
             LegendarySource,