Derive mode from DSN function

- Add headers in all files
- Minor field name changes

src/Document.php

@@ -1,4 +1,10 @@
-<?php declare(strict_types=1);
+<?php
+/**
+ * @author Daniel J. Summers <daniel@bitbadger.solutions>
+ * @license MIT
+ */
+
+declare(strict_types=1);
 
 namespace BitBadger\PDODocument;
 
@@ -18,7 +24,7 @@ class Document
     {
         $doInsert = fn() => Custom::nonQuery(Query::insert($tableName), Parameters::json(':data', $document));
 
-        if (Configuration::$autoId == AutoId::None) {
+        if (Configuration::$autoId === AutoId::None) {
             $doInsert();
             return;
         }