Feature/english (#381)

* perf[navbar]: set langSelect to component && refine errorLog component

* feat[login]:add 18n to login form

* fix[pagination]: fixed when selected page-sizes

* perf[i18n]:dashboard document svg permission

* perf[charts]: perf effect

* perf[i18n]:excel && zip

* perf[i18n]: table && errorLog && theme

* perf[i18n]: components

* perf[i18n]: direct use $t

* perf[i18n]: complex-table

* update README.md

* update README.md 📘

* perf[i18n]: refine code comments

src/views/permission/index.vue

@@ -1,7 +1,7 @@
 <template>
   <div class="app-container">
-    <div style="margin-bottom:15px;">你的权限： {{roles}}</div>
-    切换权限：
+    <div style="margin-bottom:15px;">{{$t('permission.roles')}}： {{roles}}</div>
+    {{$t('permission.switchRoles')}}：
     <el-radio-group v-model="role">
       <el-radio-button label="editor"></el-radio-button>
     </el-radio-group>