docs: Add missing favicon (fix vuejs#3001)

Author: BARNZ

docs/.vuepress/config.js

@@ -31,6 +31,12 @@ module.exports = {
         description: 'Routeur officiel pour Vue.Js'
     }
   },
+  head: [
+    ['link', { rel: 'icon', href: `/logo.png` }],
+    ['link', { rel: 'apple-touch-icon', href: `/icons/apple-touch-icon-152x152.png` }],
+    ['link', { rel: 'mask-icon', href: '/icons/safari-pinned-tab.svg', color: '#3eaf7c' }],
+    ['meta', { name: 'msapplication-TileImage', content: '/icons/msapplication-icon-144x144.png' }],
+  ],
   serviceWorker: true,
   theme: 'vue',
   themeConfig: {