Coveo: Add new product category facet (#340)

Author: lamATnginx

layouts/partials/coveo-atomic.html

@@ -20,6 +20,7 @@
       <!-- Facet Section -->
       <atomic-layout-section section="facets">
         <atomic-facet field="f5_product" label="Show by product"></atomic-facet>
+        <atomic-facet field="f5_product_grouping" label="Show by product group"></atomic-facet>
         <atomic-facet field="language" label="Show by language"></atomic-facet>
         <atomic-facet field="f5_document_type" label="Show by type"></atomic-facet>
       </atomic-layout-section>