Update dev index with a product block element

Adding a new product block element example article to the dev index

Author: rcrphillips

dotcom-rendering/src/server/dev-index.html

@@ -528,6 +528,11 @@ <h2>Test Articles By Element (Missing)</h2>
 					article:
 						'/world/2018/dec/28/south-koreas-sexist-sex-education',
 				},
+				{
+					name: 'ProductBlockElement',
+					article:
+						'/thefilter/2026/jul/02/jess-cartner-morleys-july-style-essentials-2026',
+				},
 				{
 					name: 'RichLinkBlockElement',
 					article: