update readme

README.md

@@ -1,11 +1,45 @@
 # Shadow-DOM-inject-styles
 A helper function to easily modify Shadow DOM CSS.
 
+## Install
+```bash
+npm install shadow-dom-inject-styles --save
+```
+
+## Vanilla JS Example / Demo
+[jsfiddle](https://jsfiddle.net/ry4sbnom/1/)
+
+```html
+<script type="module">
+  import {injectStyles} from 'https://unpkg.com/shadow-dom-inject-styles@latest/dist/index.js';
+
+  setTimeout(() => {
+
+    const toolbar = document.querySelector('ion-app > ion-header > ion-toolbar');
+
+    // language=CSS
+    const styles = `
+        .toolbar-background {
+            background: red !important;
+        }
+        .toolbar-container {
+            color: #fff !important;
+        }
+    `;
+
+    injectStyles(toolbar, '.toolbar-background', styles);
+
+  }, 200);
+</script>
+```
+
+## Typescript Example
+
 ```ts
 import {injectStyles} from 'shadow-dom-inject-styles';
 
 const toolbar = (this.el.querySelector('ion-header > ion-toolbar') as HTMLElement);
-    
+
 // language=CSS
 const styles = `
   .toolbar-background {
@@ -14,4 +48,4 @@ const styles = `
 `;
 
 injectStyles(toolbar, '.toolbar-background', styles);
-```
+```