FEATURE #1550: add basic sitemap

Probably will not work, because Laravel prepends first line of document with some spaces or what. However maybe its just behavior on my localhost.

app/Http/Controllers/Sitemap.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use App\Http\Requests;
+use App\Models\Content;
+
+class Sitemap extends Controller
+{
+    /**
+     * @var Content
+     */
+    private $content;
+
+    /**
+     * Sitemap constructor.
+     *
+     * @param Content $content
+     */
+    public function __construct(Content $content)
+    {
+        $this->content = $content;
+    }
+
+    public function getMap()
+    {
+        $pages = $this->content->getPageQuery()
+                               ->get();
+
+
+        foreach ($pages as $page) {
+            if ($page->is_homepage) {
+                $route = route('page.index');
+                $priority = 1;
+            } else {
+                $route = route('page.content', ['url' => $page->url]);
+                $priority = 0.8;
+            }
+
+            \Sitemap::addTag($route, $page->updated_at, 'daily', $priority);
+
+        }
+
+        return \Sitemap::render();
+    }
+}