Add title to page template (#7094)

lettre/templates/page.html

@@ -4,6 +4,8 @@
 <main class="wp-block-group"><!-- wp:group {"layout":{"inherit":true}} -->
 <div class="wp-block-group">
 
+<!-- wp:post-title {"level":1} /-->
+
 <!-- wp:spacer {"height":"1px"} -->
 <div style="height:1px" aria-hidden="true" class="wp-block-spacer"></div>
 <!-- /wp:spacer -->