feat(settings): Allow settings to update UI using fetch_settings command

desktop/types.ts

@@ -71,4 +71,9 @@ export type DownloadableMetadata = {
   id: string,
   version: string,
   downloadType: DownloadableType
+}
+
+export type Settings = {
+  autostart: boolean,
+  maxDownloadThreads: number,
 }