feat(controller): add HTMLSitemapController for generating HTML sitemap

- Added HTMLSitemapController to generate sitemap with cached data
- Updated footer.blade.php and index.blade.php for sitemap links

app/Http/Controllers/HTMLSitemapController.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use App\Models\Champion;
+use App\Models\ChampionSkin;
+use App\Models\SummonerIcon;
+use Illuminate\Support\Facades\Cache;
+
+use Spatie\Sheets\Facades\Sheets;
+
+
+class HTMLSitemapController extends Controller
+{
+    public function index()
+    {
+        $twentyHoursInSeconds = 60 * 60 * 20;
+
+        $champions = Cache::remember('sitemap_championsCache', $twentyHoursInSeconds, fn () => Champion::orderBy('name')->get());
+        $skins = Cache::remember('sitemap_championSkinsCache', $twentyHoursInSeconds, fn () => ChampionSkin::orderBy('skin_name')->get());
+        $icons = Cache::remember('sitemap_iconsCache', $twentyHoursInSeconds, fn () => SummonerIcon::orderBy('title')->get());
+        $posts = Sheets::all()->sortByDesc('date');
+
+
+        return view('sitemap.index', compact('champions', 'skins', 'icons', 'posts'));
+    }
+}