Added PWA support (#543)

* Added PWA support

* feat: added PWA plugin dependency

Author: NataliaTepluhina

package.json

@@ -1,5 +1,6 @@
 {
   "devDependencies": {
+    "@vuepress/plugin-pwa": "^1.5.4",
     "node-sass": "^4.13.1",
     "sass-loader": "^8.0.2",
     "vuepress": "^1.5.4"

src/.vuepress/config.js

@@ -228,12 +228,34 @@ module.exports = {
         href: '/logo.png'
       }
     ],
+    ['link', { rel: 'manifest', href: '/manifest.json' }],
+    ['meta', { name: 'theme-color', content: '#3eaf7c' }],
+    ['meta', { name: 'apple-mobile-web-app-capable', content: 'yes' }],
     [
-      'script',
+      'meta',
+      { name: 'apple-mobile-web-app-status-bar-style', content: 'black' }
+    ],
+    [
+      'link',
       {
-        src: 'https://player.vimeo.com/api/player.js'
+        rel: 'apple-touch-icon',
+        href: '/images/icons/apple-icon-152x152.png'
       }
     ],
+    [
+      'meta',
+      {
+        name: 'msapplication-TileImage',
+        content: '/images/icons/ms-icon-144x144.png'
+      }
+    ],
+    ['meta', { name: 'msapplication-TileColor', content: '#000000' }],
+    [
+      ('script',
+      {
+        src: 'https://player.vimeo.com/api/player.js'
+      })
+    ],
     [
       'script',
       {
@@ -317,7 +339,8 @@ module.exports = {
               },
               {
                 text: 'Vue Test Utils',
-                link: 'https://vuejs.github.io/vue-test-utils-next-docs/guide/introduction.html'
+                link:
+                  'https://vuejs.github.io/vue-test-utils-next-docs/guide/introduction.html'
               },
               {
                 text: 'Devtools',