Specify that es2020 is required (#193)

* Specify that `es2020` is required

* Update README.md

* Update README.md

* Add section on vite to `index.html`

* Remove section on bundlers from `README.md`

docs/cubing/index.html

@@ -130,6 +130,15 @@ <h1><a href="#javascript"><code>npm</code> package</a></h1>
         The <code>npm</code> package should work with any modern bundlers and tools. If you are having trouble, make sure your tool is compatible with ES2020 syntax. We recommend using <a href="https://esbuild.github.io/"><code>esbuild</code></a> or tools based on <code>esbuild</code>, and you may find <a href="https://github.com/cubing/cubing-app-template">this project template</a> a helpful start.
       </p>
     </section>
+    <section id="vite">
+      <h1>Using with Vite</h1>
+      <p>
+        By default, <a href="https://vitejs.dev/">Vite</a>, an <code>esbuild</code>-based bundler, transpiles code to ES2019. To use the <code>npm</code> package with Vite, add this to your <code>vite.config.js</code>:
+        <code class="sample">
+          <span>export default {build: {target: "es2020"}}</span>
+        </code>
+      </p>
+    </section>
 
     <section id="code-experiments">
       <h1><a href="#code-experiments">Code Experiments</a></h1>