404: add spacer blocks for breathing room around the search form

templates/404.html

@@ -3,14 +3,20 @@
 <!-- wp:group {"tagName":"main","layout":{"type":"constrained"}} -->
 <main class="wp-block-group">
 	<!-- wp:heading {"level":1} -->
-	<h1 class="wp-block-heading">Not found</h1>
+	<h1 class="wp-block-heading">404 - Not found</h1>
 	<!-- /wp:heading -->
 	<!-- wp:group {"style":{"spacing":{"padding":{"top":"var:preset|spacing|60","bottom":"var:preset|spacing|60"}}},"layout":{"type":"constrained"}} -->
 	<div class="wp-block-group" style="padding-top:var(--wp--preset--spacing--60);padding-bottom:var(--wp--preset--spacing--60)">
+		<!-- wp:spacer -->
+		<div style="height:50px" aria-hidden="true" class="wp-block-spacer"></div>
+		<!-- /wp:spacer -->
 		<!-- wp:paragraph -->
-		<p>That page doesn't exist. Try a search, or head <a href="/">home</a>.</p>
+		<h3>Perhaps you'd like to try a search, or head <a href="/">home</a>.</h3>
 		<!-- /wp:paragraph -->
 		<!-- wp:search {"label":"Search","buttonText":"Search"} /-->
+		<!-- wp:spacer -->
+		<div style="height:100px" aria-hidden="true" class="wp-block-spacer"></div>
+		<!-- /wp:spacer -->
 	</div>
 	<!-- /wp:group -->
 </main>