docs: api update example with router.START_LOCATION (#3531)

Co-authored-by: Eduardo San Martin Morote <[email protected]>

Author: Alex-Sokolov

docs/api/README.md

@@ -349,14 +349,14 @@ Since it's just a component, it works with `<transition>` and `<keep-alive>`. Wh
   Initial route location represented as a [Route Object](#the-route-object) where the router starts at. Can be used in navigation guards to differentiate the initial navigation.
 
   ```js
-  import Router from 'vue-router'
+  import VueRouter from 'vue-router'
 
-  const router = new Router({
+  const router = new VueRouter({
     // ...
   })
 
   router.beforeEach((to, from) => {
-    if (from === START_LOCATION) {
+    if (from === VueRouter.START_LOCATION) {
       // initial navigation
     }
   })

docs/ru/api/README.md

@@ -349,14 +349,14 @@ sidebar: auto
   Первоначальная навигация будет [объектом Route](#объект-route) с которого запускается маршрутизатор. Можно использовать в навигационных хуках для определения стартовой навигации.
 
   ```js
-  import Router from 'vue-router'
+  import VueRouter from 'vue-router'
 
-  const router = new Router({
+  const router = new VueRouter({
     // ...
   })
 
   router.beforeEach((to, from) => {
-    if (from === START_LOCATION) {
+    if (from === VueRouter.START_LOCATION) {
       // первоначальная навигация
     }
   })

docs/zh/api/README.md

@@ -330,14 +330,14 @@ sidebar: auto
   以[路由对象](#路由对象)的格式展示初始路由地址，即路由开始的地方。可用在导航守卫中以区分初始导航。
 
   ```js
-  import Router from 'vue-router'
+  import VueRouter from 'vue-router'
 
-  const router = new Router({
+  const router = new VueRouter({
     // ...
   })
 
   router.beforeEach((to, from) => {
-    if (from === START_LOCATION) {
+    if (from === VueRouter.START_LOCATION) {
       // 初始导航
     }
   })