Add more testing stuff

vitest-example/HelloWorld.test.tsx

@@ -0,0 +1,8 @@
+import { render } from "@solidjs/testing-library";
+import { expect, test } from "vitest";
+import HelloWorld from "./HelloWorld.tsx";
+
+test("renders name", async () => {
+	const { getByText } = await render(<HelloWorld name="Vitest" />);
+	await expect.element(getByText("Hello Vitest!")).toBeInTheDocument();
+});