feat: update playground versions

Author: zzcr

examples/sites/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@opentiny/vue-docs",
-  "version": "3.20.7",
+  "version": "3.21.0",
   "license": "MIT",
   "scripts": {
     "start": "vite",

examples/sites/playground/App.vue

@@ -11,7 +11,7 @@ import logoUrl from './assets/opentiny-logo.svg?url'
 import GitHub from './icons/Github.vue'
 import Share from './icons/Share.vue'
 
-const VERSION = 'tiny-vue-version-3.20'
+const VERSION = 'tiny-vue-version-3.21'
 const NOTIFY_KEY = 'tiny-vue-playground-notify'
 const LAYOUT = 'playground-layout'
 const LAYOUT_REVERSE = 'playground-layout-reverse'
@@ -23,7 +23,7 @@ const isMobileFirst = tinyMode === 'mobile-first'
 const isSaas = tinyTheme === 'saas'
 const isPreview = searchObj.get('openMode') === 'preview' // 是否多端弹窗预览
 
-const versions = ['3.20', '3.19', '3.18']
+const versions = ['3.21', '3.20', '3.19']
 const getVersion = () => {
   if (isPreview) {
     return versions[0]