update docs

Author: hunterliu1003

README.md

@@ -60,7 +60,7 @@ UMD builds can be used directly in the browser via a `<script>` tag.
 ```
 
 ```js
-import VueFinalModal from 'vue-final-modal'
+import { VueFinalModal } from 'vue-final-modal'
 
 export default {
   components: {

docs/README.md

@@ -60,7 +60,7 @@ UMD builds can be used directly in the browser via a `<script>` tag.
 ```
 
 ```js
-import VueFinalModal from 'vue-final-modal'
+import { VueFinalModal } from 'vue-final-modal'
 
 export default {
   components: {

docs/content/en/setup.md

@@ -45,9 +45,9 @@ export default {
 ```js[main.js]
 
 
-import VueFinalModal from 'vue-final-modal'
+import { VueFinalModal } from 'vue-final-modal'
 
-Vue.use(VueFinalModal)
+Vue.component('VueFinalModal', VueFinalModal)
 ```
 
 ## Server Side Render
@@ -65,9 +65,9 @@ export default {
 ```js[vue-final-modal.js]
 
 
-import VueFinalModal from 'vue-final-modal/plugin'
+import { VueFinalModal } from 'vue-final-modal'
 
-Vue.use(VueFinalModal)
+Vue.component('VueFinalModal', VueFinalModal)
 ```
 
 ## CDN