Add Interface Scale setting to zoom the whole app (80-200%)

src-tauri/src/lib.rs

@@ -103,6 +103,7 @@ pub fn run() {
             commands::set_font_size,
             commands::set_font_family,
             commands::set_line_height,
+            commands::set_ui_scale,
             commands::get_notebooks,
             commands::count_root_notes,
             commands::create_notebook,