feat: support external script link install

Author: hacke2

README.md

@@ -34,7 +34,7 @@ yarn add vue-append
 
 ### appended
 
-- if html append and no throw error, it will fire `appended` event.
+- if html append , script downloaded and no throw error, it will fire `appended` event.
 
 ### appenderr
 
@@ -63,6 +63,10 @@ Vue.use(VueAppend);
 
 const html = `
 <div id="test">1</div>
+<script
+  src="https://code.jquery.com/jquery-3.4.1.min.js"
+  integrity="sha256-CSXorXvZcTkaix6Yvo6HppcZGetbYMGWSFlBw8HfCJo="
+  crossorigin="anonymous"></script>
 <script>
 var i = 1;
 setInterval(function() {
@@ -79,7 +83,9 @@ new Vue({
   },
   methods: {
     appended() {
-      console.log('appended!')
+      console.log('appended!');
+      // could use jQuery 😊
+      alert(window.jQuery);
     }
   }
 });