Update documentation and examples, add new nominal accounts features and authentication methods

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

examples/14_generate_client_secret.php

@@ -14,8 +14,10 @@ use Apoloz\AlfaBank\Enums\Environment;
  * Run this ONCE when setting up the project or if you lose your secret.
  * 
  * Requirements:
- * 1. You have the `client_id` (from the bank/portal).
+ * 1. You have the `client_id` (Found in Developer Portal -> App Settings URL or Overview).
  * 2. You have the TLS certificates (.pem/.key) authorized by the bank.
+ *    - Prod: You sent CSR to bank, they enabled integration and sent .cer back.
+ *    - Sandbox: You downloaded them from the email/portal.
  */
 
 // 1. Configuration