implement community basics

src/Repository/CommunityRepository.php

@@ -0,0 +1,19 @@
+<?php namespace RVR\Repository;
+
+use RVR\PersistentData\Model\Community;
+use SokoWeb\PersistentData\PersistentDataManager;
+
+class CommunityRepository
+{
+    private PersistentDataManager $pdm;
+
+    public function __construct()
+    {
+        $this->pdm = new PersistentDataManager();
+    }
+
+    public function getById(int $id): ?Community
+    {
+        return $this->pdm->selectFromDbById($id, Community::class);
+    }
+}