fix: removed docs for deprecated APIs

Author: wilburx9

lib/src/common/paystack.dart

@@ -93,13 +93,6 @@ class PaystackPlugin {
  /// [context] - the widgets BuildContext
  ///
  /// [charge] - the charge object.
- ///
- /// [beforeValidate] - Called before validation
- ///
- /// [onSuccess] - Called when the payment is completes successfully
- ///
- /// [onError] - Called when the payment completes with an unrecoverable error
- ///
 
  static Future<CheckoutResponse> chargeCard(
  BuildContext context,