cleaned up readme
cleaned up readme

Azure/azure-notificationhubs-samples,Azure/azure-notificationhubs-samples,Azure/azure-notificationhubs-samples,Azure/azure-notificationhubs-samples,Azure/azure-notificationhubs-samples,Azure/azure-notificationhubs-samples,Azure/azure-notificationhubs-samples,Azure/azure-notificationhubs-samples,Azure/azure-notificationhubs-samples