Add php cs fixer and some rule sets.

.ci/php-cs-fixer/.gitignore

@@ -0,0 +1 @@
+vendor

.ci/php-cs-fixer/.php-cs-fixer.php

@@ -0,0 +1,31 @@
+<?php
+/*
+ * .php-cs-fixer.php
+ * Copyright (c) 2022 james@firefly-iii.org
+ *
+ * This file is part of Firefly III (https://github.com/firefly-iii).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+$finder = PhpCsFixer\Finder::create();
+
+$config = new PhpCsFixer\Config();
+return $config->setRules([
+    '@PSR12' => true,
+    'strict_param' => true,
+    'array_syntax' => ['syntax' => 'short'],
+])
+              ->setFinder($finder)
+    ;

.ci/php-cs-fixer/composer.json

@@ -0,0 +1,5 @@
+{
+    "require": {
+        "friendsofphp/php-cs-fixer": "^3.12"
+    }
+}