Add checkout button

lib/bigcommerce/cart/use-open-checkout.tsx

@@ -0,0 +1,12 @@
+import useCart from './use-cart'
+
+export default function useOpenCheckout() {
+  const { data, mutate } = useCart()
+
+  return async function openCheckout() {
+    window.open(data?.redirect_urls.checkout_url)
+    console.log('URL1', data?.redirect_urls.checkout_url)
+    // Get new redirect urls
+    await mutate()
+  }
+}