Add banner advertising DataTree post (#739)

* add banner for DataTree post

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Anderson Banihirwe <[email protected]>

Author: 3 people

src/components/layout.js

@@ -13,11 +13,11 @@ export const Layout = ({
   url = 'https://xarray.dev',
   enableBanner = false,
 }) => {
-  const bannerTitle = "Xarray's 2024 User Survey is live now."
+  const bannerTitle = 'Check out the new blog post on DataTree!'
   const bannerDescription = ''
   const bannerChildren = (
-    <Link href='https://forms.gle/KEq7WviCdz9xTaJX6'>
-      Please take ~5 minutes to fill it out and help us improve Xarray.
+    <Link href='/blog/datatree'>
+      Xarray x NASA: xarray.DataTree for hierarchical data structures
     </Link>
   )
 

src/pages/index.js

@@ -17,7 +17,7 @@ export default function IndexPage() {
       card={
         'https://raw.githubusercontent.com/xarray-contrib/xarray.dev/main/public/Xarray-assets/Icon/Xarray_Icon_Final.png'
       }
-      // enableBanner
+      enableBanner
     >
       <HeroBanner />
       <Features />