Update sponsorship banner in docs

docs/_static/custom.css

@@ -8,9 +8,3 @@ pre .sd {
   color: #BBBBDD;
   font-style: italic;
 }
-
-.sponsor {
-  font-size: 0.9em;
-  line-height: 1.2em;
-  text-decoration: none;
-}

docs/_templates/sponsor.html

@@ -1,13 +1,3 @@
-<a class="sponsor d-block border rounded p-1 mt-5" href="https://www.coderedcorp.com/">
-  <div class="row no-gutters">
-    <div class="col-3">
-      <img src="https://docs.coderedcorp.com/logo-square-red-128.png" class="w-100 rounded" alt=""/>
-    </div>
-    <div class="col-9">
-      <p class="p-2 m-0">
-        <strong>Get Pro Support</strong><br>
-        This project is commercially supported by CodeRed.
-      </p>
-    </div>
-  </div>
+<a href="https://www.codered.cloud/?utm_source=docs-wagtail-crx&utm_medium=banner">
+  <img src="https://docs.coderedcorp.com/crcloud-docs-ad.webp" alt="Wagtail Hosting by CodeRed" class="w-100">
 </a>