add reset button (about)

src/client/js/components/Admin/SlackIntegration/CustomBotWithoutProxySettings.jsx

@@ -30,6 +30,7 @@ const CustomBotWithoutProxySettings = (props) => {
 
       <h2 className="admin-setting-header">{t('admin:slack_integration.custom_bot_without_proxy_settings')}</h2>
 
+      <btn className="pull-right btn btn-danger" type="button">リセット</btn>
       <div className="my-5 mx-3">
         <CustomBotWithoutProxySettingsAccordion
           {...props}