opt.

- add help for ssh virt keys
- rm unused lib

windows/flutter/generated_plugin_registrant.cc

@@ -6,13 +6,10 @@
 
 #include "generated_plugin_registrant.h"
 
-#include <flutter_volume_controller/flutter_volume_controller_plugin_c_api.h>
 #include <share_plus/share_plus_windows_plugin_c_api.h>
 #include <url_launcher_windows/url_launcher_windows.h>
 
 void RegisterPlugins(flutter::PluginRegistry* registry) {
-  FlutterVolumeControllerPluginCApiRegisterWithRegistrar(
-      registry->GetRegistrarForPlugin("FlutterVolumeControllerPluginCApi"));
   SharePlusWindowsPluginCApiRegisterWithRegistrar(
       registry->GetRegistrarForPlugin("SharePlusWindowsPluginCApi"));
   UrlLauncherWindowsRegisterWithRegistrar(

windows/flutter/generated_plugins.cmake

@@ -3,7 +3,6 @@
 #
 
 list(APPEND FLUTTER_PLUGIN_LIST
-  flutter_volume_controller
   share_plus
   url_launcher_windows
 )