message: Expose styling types for `slider` in `iced_web`
diff: //! [`State`]: struct.State.html
  use crate::{Bus, Css, Element, Length, Widget};
  +pub use iced_style::slider::{Handle, HandleShape, Style, StyleSheet};
  +
  use dodrio::bumpalo;
  use std::{ops::RangeInclusive, rc::Rc};
  @@ -38,6 +40,7 @@ pub struct Slider<'a, Message> {
  value: f32,
  on_change: Rc<Box<dyn Fn(f32) -> Message>>,
  width: Length,
  + style: Box<dyn StyleSheet>,
  }
  impl<'a, Message> Slider<'a, Message> {
  @@ -68,6 +71,7 @@ impl<'a, Message> Slider<'a, Message> {
  range,
  on_change: Rc::new(Box::new(on_change)),
  width: Length::Fill,
  + style: Default::default(),
  }
  }
  @@ -78,6 +82,14 @@ impl<'a, Message> Slider<'a, Message> {
  self.width = width;
  self
  }
  +
  + /// Sets the style of the [`Slider`].
  + ///
  + /// [`Slider`]: struct.Slider.html
  + pub fn style(mut self, style: impl Into<Box<dyn StyleSheet>>) -> Self {
  + self.style = style.into();
  + self
  + }
  }
  impl<'a, Message> Widget<Message> for Slider<'a, Message>
  @@ -103,7 +115,7 @@ where
  let event_bus = bus.clone();
  // TODO: Make `step` configurable
  - // TODO: Complete styling
  + // TODO: Styling
  input(bump)
  .attr("type", "range")
  .attr("step", "0.01")
  