Rainfall: adjust featured image in single template (#6489)

* Set single post featured image to wide align

* Add height to featured image

rainfall/templates/single.html

@@ -18,7 +18,7 @@
 <!-- wp:spacer {"height":"10px"} -->
 <div style="height:10px" aria-hidden="true" class="wp-block-spacer"></div>
 <!-- /wp:spacer -->
-<!-- wp:post-featured-image {"align":"full"} /-->
+<!-- wp:post-featured-image {"align":"wide","height":"30rem"} /-->
 <!-- wp:spacer {"height":"10px"} -->
 <div style="height:10px" aria-hidden="true" class="wp-block-spacer"></div>
 <!-- /wp:spacer -->