Create a class to produce web page

fn main() {
    let mut web_page = WebPage::new();

    web_page.set_title(String::from("Rust web page"));
    web_page.set_body(String::from("Some text ...."));
    web_page.set_body_color(String::from("red"));
    web_page.set_body_font(String::from("Helvetica"));
    web_page.set_body_size(String::from("12"));
    web_page.set_body_weight(String::from("bold"));
    println!("{}", web_page.render());
}