Implement dark mode theme (#744)

Co-authored-by: DevilXD <4180725+DevilXD@users.noreply.github.com>

lang/Indonesian.json

@@ -134,6 +134,7 @@
                 "autostart": "Mulai secara otomatis :",
                 "tray": "Mulai otomatis di bilah tugas :",
                 "tray_notifications": "Pemberitahuan bilah tugas :",
+                "dark_mode": "Mode gelap: ",
                 "priority_only": "Prioritas saja :",
                 "proxy": "Proksi (harus dimulai ulang) :"
             },