Write documentation for new iced_wgpu types

wgpu/src/target.rs

@@ -3,6 +3,12 @@ use crate::Viewport;
 /// A rendering target.
 #[derive(Debug)]
 pub struct Target<'a> {
+    /// The texture where graphics will be rendered.
     pub texture: &'a wgpu::TextureView,
+
+    /// The viewport of the target.
+    ///
+    /// Most of the time, you will want this to match the dimensions of the
+    /// texture.
     pub viewport: &'a Viewport,
 }