Verso: Add 404 template (#7027)

* Add 404 template

* Fix spacing

verso/templates/404.html

@@ -0,0 +1,10 @@
+<!-- wp:template-part {"slug":"header","tagName":"header"} /-->
+
+<!-- wp:group {"tagName":"main","layout":{"type":"constrained"}} -->
+<main class="wp-block-group">
+    <!-- wp:pattern {"slug":"verso/hidden-no-results-content"} /-->
+    <!-- wp:search {"label":"","showLabel":false,"placeholder":"Search here...","buttonText":"Search"} /-->
+</main>
+<!-- /wp:group -->
+    
+<!-- wp:template-part {"slug":"footer","tagName":"footer"} /-->