MainWindow: Do not use mnemonics

Author: ryonakano

src/MainWindow.vala

@@ -96,17 +96,17 @@ public class Atlas.MainWindow : Adw.ApplicationWindow {
         search_res_popover.set_parent (search_entry);
 
         var style_submenu = new Menu ();
-        style_submenu.append (_("S_ystem"), "app.color-scheme('%s')".printf (Define.ColorScheme.DEFAULT));
-        style_submenu.append (_("_Light"), "app.color-scheme('%s')".printf (Define.ColorScheme.FORCE_LIGHT));
-        style_submenu.append (_("_Dark"), "app.color-scheme('%s')".printf (Define.ColorScheme.FORCE_DARK));
+        style_submenu.append (_("System"), "app.color-scheme('%s')".printf (Define.ColorScheme.DEFAULT));
+        style_submenu.append (_("Light"), "app.color-scheme('%s')".printf (Define.ColorScheme.FORCE_LIGHT));
+        style_submenu.append (_("Dark"), "app.color-scheme('%s')".printf (Define.ColorScheme.FORCE_DARK));
 
         var map_source_submenu = new Menu ();
-        map_source_submenu.append (_("Map_nik"), "win.map-source('%s')".printf (Define.MapSource.MAPNIK));
-        map_source_submenu.append (_("_Transport"), "win.map-source('%s')".printf (Define.MapSource.TRANSPORT));
+        map_source_submenu.append (_("Mapnik"), "win.map-source('%s')".printf (Define.MapSource.MAPNIK));
+        map_source_submenu.append (_("Transport"), "win.map-source('%s')".printf (Define.MapSource.TRANSPORT));
 
         var main_menu = new Menu ();
-        main_menu.append_submenu (_("_Style"), style_submenu);
-        main_menu.append_submenu (_("_Map Source"), map_source_submenu);
+        main_menu.append_submenu (_("Style"), style_submenu);
+        main_menu.append_submenu (_("Map Source"), map_source_submenu);
 
         var menu_button = new Gtk.MenuButton () {
             tooltip_text = _("Main Menu"),