docs: Adjust quotes on install instructions

Author: Jasenkoo

README.md

@@ -42,7 +42,7 @@ Import and register component
 import { createApp } from "vue";
 import App from './App.vue';
 
-import Datepicker from "vue3-date-time-picker";
+import Datepicker from 'vue3-date-time-picker';
 import 'vue3-date-time-picker/dist/main.css'
 
 const app = createApp(App);
@@ -53,7 +53,7 @@ app.component("Datepicker", Datepicker);
 
 ```vue
 <script>
-    import Datepicker from "vue3-date-time-picker";
+    import Datepicker from 'vue3-date-time-picker';
     import 'vue3-date-time-picker/dist/main.css'
     
     export default {