v6.0.0+1 of athmovil_checkout_flutter

Flutter plugin for integrating the ATH Móvil Payment Secure Button on Android and iOS. Changelog excerpt: - Updated plugin metadata for pub.dev publication. - Improved README documentation and installation steps. - Updated example app to a modern Flutter-compatible project. - Added compatibility improvements for Android and iOS builds. - Updated dependencies and project configuration. - New ATHMovilPaymentSecureButton: ``` `ATHMovilPaymentSecureButton(style: Style.orange, lang: Lang.en, athMovilPayment: ATHMovilPayment(), //ATHMovilPayment listener: this,) //ATHMovilPaymentResponseListener```` - N[...]