[sf::Window's] constructor accepts a third optional argument: a style, which allows to choose which decorations and features you want. You can use any combination of the following styles:
- sf::Style::None No decoration at all (useful for splash screens, for example); this style cannot be combined with others
- sf::Style::Titlebar The window has a titlebar
- sf::Style::Resize The window can be resized and has a maximize button
- sf::Style::Close The window has a close button
- sf::Style::Fullscreen The window is shown in fullscreen mode; this style cannot be combined with others, and requires a valid video mode
- sf::Style::Default The default style, which is a shortcut for Titlebar | Resize | Close