Please export type for ToastOptions

[KostiantynO]

Describe the feature 📝:

I want ToastOptions interface to be exported:

export interface ToastOptions {
    className?: string;
    closeButton?: boolean;
    descriptionClassName?: string;
    style?: React.CSSProperties;
    cancelButtonStyle?: React.CSSProperties;
    actionButtonStyle?: React.CSSProperties;
    duration?: number;
    unstyled?: boolean;
    classNames?: ToastClassnames;
}

[emilkowalski]

Merged #399