🚚 Move homepage sponsors and contributors to example site

The theme homepage no longer renders blowfish.page's sponsor and
contributor sections; the example site overrides index.html instead,
so user sites don't inherit the theme repo's data files.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

exampleSite/layouts/index.html

@@ -0,0 +1,13 @@
+{{/* blowfish.page homepage: theme layout switcher plus site-specific sponsors and contributors. */}}
+{{ define "main" }}
+  {{ partial "home/layout-switcher.html" . }}
+  {{ $jsHome := resources.Get "js/home.js" | resources.Minify | resources.Fingerprint (.Site.Params.fingerprintAlgorithm | default "sha512") }}
+  <script defer type="text/javascript" src="{{ $jsHome.RelPermalink }}" integrity="{{ $jsHome.Data.Integrity }}"></script>
+  <section class="mx-auto max-w-7xl px-4 sm:px-6 lg:px-8">
+    {{ partial "sponsors.html" . }}
+    {{ partial "contributors.html" . }}
+  </section>
+  <section>
+    {{ partial "recent-articles/main.html" . }}
+  </section>
+{{ end }}