Next.js Commerce refresh. (#966)

We're making some updates to Next.js Commerce. Everything prior to this commit marks what we're calling [`v1`](https://github.com/vercel/commerce/releases/tag/v1) as a point in time to be able to reference and still use going into the future. The current architecture of Commerce is a multi-vendor, interoperable solution, including:

- [Shopify](https://shopify.vercel.store/)
- [Swell](https://swell.vercel.store/)
- [BigCommerce](https://bigcommerce.vercel.store/)
- [Vendure](https://vendure.vercel.store/)
- [Saleor](https://saleor.vercel.store/)
- [Ordercloud](https://ordercloud.vercel.store/)
- [Spree](https://spree.vercel.store/)
- [Kibo Commerce](https://kibocommerce.vercel.store/)
- [Commerce.js](https://commercejs.vercel.store/)
- [SalesForce Cloud Commerce](https://salesforce-cloud-commerce.vercel.store/)

All features can be toggled on or off, and it's easy to change between commerce providers. To support this, we needed to create a ["commerce metaframework"](d1d9e8c434/packages/commerce/new-provider.md) where providers could confirm to an API spec to add support for Next.js Commerce. While this worked and was successful for `v1`, we have different design goals and ambitions for `v2`.

**What You Need To Know**

- `v1` will not be updated moving forward. If you need to reference `v1`, you will still be able to clone and deploy the version tagged at this release.
- `v2` will be shifting to be a single provider vs. provider agnostic. Other providers are welcome to fork this repository and swap out the underlying `lib/` implementation that connects to the selected commerce provider (Shopify). This architecture was chosen to reduce the surface area of the codebase, remove the intermediate metaframework layer for provider-interoperability, and enable usage with the latest Next.js and React features.
- We will be sharing more about `v2` in the future as we continue to iterate before the marked release.

components/layout/navbar/search.tsx

@@ -0,0 +1,42 @@
+'use client';
+
+import { useRouter, useSearchParams } from 'next/navigation';
+
+import SearchIcon from 'components/icons/search';
+
+export default function Search() {
+  const router = useRouter();
+  const searchParams = useSearchParams();
+
+  function onSubmit(e: React.FormEvent<HTMLFormElement>) {
+    e.preventDefault();
+
+    const val = e.target as HTMLFormElement;
+    const search = val.search as HTMLInputElement;
+
+    if (search.value) {
+      router.push(`/search?q=${search.value}`);
+    } else {
+      router.push(`/search`);
+    }
+  }
+
+  return (
+    <form
+      onSubmit={onSubmit}
+      className="relative m-0 flex w-full items-center border border-gray-200 bg-transparent p-0 dark:border-gray-500"
+    >
+      <input
+        type="text"
+        name="search"
+        placeholder="Search for products..."
+        autoComplete="off"
+        defaultValue={searchParams?.get('q') || ''}
+        className="w-full py-2 px-4 text-black dark:bg-black dark:text-gray-100"
+      />
+      <div className="absolute top-0 right-0 mr-3 flex h-full items-center">
+        <SearchIcon className="h-5" />
+      </div>
+    </form>
+  );
+}