Enhance README and refactor code structure for improved functionality

- Updated README.md with detailed project description, features, and installation instructions.
- Refactored functions.php to include configuration settings and improved database handling.
- Modified index.php for better user experience and added pagination controls.
- Introduced new utility functions for API handling and database interactions.
- Added CSS styles for improved layout and visibility of elements.
- Removed vault.csv as data is now managed through the database.
- Implemented FTP deployment workflow for automated deployment.
- Added exception handling classes for better error management.
- Created JavaScript functions for pagination of transaction records.

includes/exceptions.php

@@ -0,0 +1,24 @@
+<?php
+class ApiKeyMissingException extends Exception {
+  public function __construct($message, $code = 0, Throwable $previous = null) {
+    parent::__construct($message, $code, $previous);
+  }
+}
+
+class CurlErrorException extends Exception {
+  public function __construct($message, $code = 0, Throwable $previous = null) {
+    parent::__construct($message, $code, $previous);
+  }
+}
+
+class JsonDataException extends Exception {
+  public function __construct($message, $code = 0, Throwable $previous = null) {
+    parent::__construct($message, $code, $previous);
+  }
+}
+
+class ApiValidationException extends Exception {
+  public function __construct($message, $code = 0, Throwable $previous = null) {
+    parent::__construct($message, $code, $previous);
+  }
+}