keyboard: show logo on demand with circle + L

reform2-keyboard-fw/menu.c

@@ -159,6 +159,10 @@ int execute_meta_function(int keycode) {
   else if (keycode == KEY_X) {
     jump_to_bootloader();
   }
+  else if (keycode == KEY_L) {
+    anim_hello();
+    return 0;
+  }
 
   gfx_clear();
   gfx_flush();