refactor(website): extract layouts and use more server components (#9027)

Closes https://github.com/discordjs/discord.js/issues/8920
Closes https://github.com/discordjs/discord.js/issues/8997

apps/website/src/util/members.ts

@@ -0,0 +1,37 @@
+import type { ApiItem, ApiItemContainerMixin } from '@microsoft/api-extractor-model';
+
+/**
+ * Resolves all inherited members (including merged members) of a given parent.
+ *
+ * @param parent - The parent to resolve the inherited members of.
+ * @param predicate - A predicate to filter the members by.
+ */
+export function resolveMembers<T extends ApiItem>(
+	parent: ApiItemContainerMixin,
+	predicate: (item: ApiItem) => item is T,
+) {
+	const seenItems = new Set<string>();
+	const inheritedMembers = parent.findMembersWithInheritance().items.reduce((acc, item) => {
+		if (predicate(item)) {
+			acc.push({
+				item,
+				inherited:
+					item.parent?.containerKey === parent.containerKey
+						? undefined
+						: (item.parent as ApiItemContainerMixin | undefined),
+			});
+			seenItems.add(item.containerKey);
+		}
+
+		return acc;
+	}, new Array<{ inherited?: ApiItemContainerMixin | undefined; item: T }>());
+
+	const mergedMembers = parent
+		.getMergedSiblings()
+		.filter((sibling) => sibling.containerKey !== parent.containerKey)
+		.flatMap((sibling) => (sibling as ApiItemContainerMixin).findMembersWithInheritance().items)
+		.filter((item) => predicate(item) && !seenItems.has(item.containerKey))
+		.map((item) => ({ item: item as T, inherited: item.parent ? (item.parent as ApiItemContainerMixin) : undefined }));
+
+	return [...inheritedMembers, ...mergedMembers];
+}