docs: add version filter for algolia search

Author: meteorlxy

packages/docs/docs/.vuepress/config.js

@@ -33,7 +33,10 @@ module.exports = ctx => ({
     // #697 Provided by the official algolia team.
     algolia: ctx.isProd ? ({
       apiKey: '3a539aab83105f01761a137c61004d85',
-      indexName: 'vuepress'
+      indexName: 'vuepress',
+      algoliaOptions: {
+        facetFilters: ['tags:v1']
+      }
     }) : null,
     smoothScroll: true,
     locales: {