[Docs Site] Consider additional_groups in products.ts (#21763)

* [Docs Site] Consider additional_groups in products.ts

* formatting

Author: KianNH

src/util/products.ts

@@ -3,12 +3,34 @@ import { getCollection } from "astro:content";
 export const products = await getCollection("products");
 
 export const productsByGroup = Object.entries(
-	Object.groupBy(
-		products.filter((product) => Boolean(product.data.product.group)),
-		(product) => product.data.product.group,
-	),
+	products
+		.filter((product) => Boolean(product.data.product.group))
+		.reduce(
+			(groups, product) => {
+				const primaryGroup = product.data.product.group;
+				const additionalGroups = product.data.product.additional_groups ?? [];
+				const allGroups = [primaryGroup, ...additionalGroups];
+
+				for (const group of allGroups) {
+					if (!groups[group]) {
+						groups[group] = [];
+					}
+					groups[group].push(product);
+				}
+
+				return groups;
+			},
+			{} as Record<string, typeof products>,
+		),
 );
 
 export const groups = [
-	...new Set(products.flatMap((product) => product.data.product.group ?? [])),
+	...new Set(
+		products.flatMap((product) =>
+			[
+				product.data.product.group,
+				...(product.data.product.additional_groups ?? []),
+			].filter(Boolean),
+		),
+	),
 ].sort();