[docs] Update Vite sample code.

Even Vite 3 still seems to have issues: vitejs/vite#9062 (comment)

docs/cubing/index.html

@@ -131,10 +131,10 @@ <h2>Compatibility</h2>
         The <code>npm</code> package should work with any modern bundlers and tools. If you are having trouble, <b>make sure your tool is compatible with ES2020 syntax</b>. 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>
       <h3>Known Issues</h3>
-      <p><a href="https://vitejs.dev/">Vite</a> 3 does not support full ES2020 by default. Use the following config:</p>
+      <p><a href="https://vitejs.dev/">Vite</a> does not support full ES2020 by default. Use the following config:</p>
       <code class="sample">
 // vite.config.js<br>
-export default {build: {target: "es2020"}};
+export default { optimizeDeps: { esbuildOptions: { target: "es2020" } } };
       </code>
     </section>
 

src/cubing/alg/Alg.ts

@@ -84,7 +84,7 @@ export class Alg extends AlgCommon<Alg> {
 
     for (const unit of this.#units) {
       if (!experimentalIsUnit(unit)) {
-        throw new Error("An alg can only contain units.");
+        throw new Error("An alg can only contain alg nodes.");
       }
     }
   }

src/cubing/alg/test/alg.spec.ts

@@ -18,7 +18,7 @@ describe("Alg", () => {
 
   it("throws an error for a nested Alg", () => {
     expect(() => new Alg([new Alg([new Move("R", 1)])])).toThrowError(
-      /An alg can only contain units./,
+      /An alg can only contain alg nodes./,
     );
   });
 });