add chapter about data repositories, and start work on perfomance chapter

app/config/settings.php

@@ -9,15 +9,4 @@ return new Settings(
     templateDir: __DIR__ . '/../templates',
     templateExtension: '.html',
     pagesPath: __DIR__ . '/../data/pages/',
-    connection: [
-        'driver' => 'pdo_sqlite',
-        'user' => '',
-        'password' => '',
-        'path' => __DIR__ . '/../data/db.sqlite',
-    ],
-    doctrine: [
-        'devMode' => true,
-        'metadataDirs' => [__DIR__ . '/../src/Model/'],
-        'cacheDir' => __DIR__ . '/../data/cache/',
-    ],
 );