Remove browser key and add in readme

README.md

@@ -10,10 +10,22 @@ $ npm install --save @github/auto-complete-element
 
 ## Usage
 
+### Script
+
+Import as ES modules:
+
 ```js
 import '@github/auto-complete-element'
 ```
 
+With a script tag:
+
+```html
+<script type="module" src="./node_modules/@github/auto-complete-element/dist/browser.js">
+```
+
+### Markup
+
 ```html
 <auto-complete src="/users/search" for="users-popup">
   <input type="text">

package.json

@@ -6,7 +6,6 @@
   "type": "module",
   "main": "dist/index.js",
   "module": "dist/index.js",
-  "browser": "dist/browser.js",
   "types": "index.d.ts",
   "scripts": {
     "clean": "rm -rf dist",