docs: update header title

Author: tangjinzhou

site/components/header.vue

@@ -35,7 +35,7 @@ export default {
           <a-col xxl={4} xl={5} lg={5} md={6} sm={24} xs={24}>
             <router-link to={{ path: '/ant-design-vue' }} id='logo'>
               <img alt='logo' height='32' src='https://raw.githubusercontent.com/vueComponent/ant-design-vue/master/logo.png' />
-              <span>  VUE-ANTD</span>
+              <span>  Ant Design Vue</span>
             </router-link>
           </a-col>
           <a-col xxl={20} xl={19} lg={19} md={18} sm={0} xs={0}>