Can not handle umlaute

[mkalinski93]

I am using version 3.0.0

the text "Zwischenboden für Arbeitstische ATK - 600 Tief" becomes "zwischenboden-fur-arbeitstische-atk-600-tief"

Most often, German umlaute are translated with two characters. For example "ö" becomes "oe"

I´ve manualy tried to set umlaute, but not working either.

This is my recent configuration

SlugHelperConfiguration slugHelperConfiguration = new SlugHelperConfiguration();
            slugHelperConfiguration.ForceLowerCase = true;
            slugHelperConfiguration.CollapseDashes = true;
            slugHelperConfiguration.TrimWhitespace = true;
            slugHelperConfiguration.CollapseWhiteSpace = true;
            services.AddSingleton(new SlugHelper(slugHelperConfiguration));