message: Make `Frame::fill` take a generic `Into<Fill>`
  This can be used to improve readability by using your own types.
diff: @@ -89,14 +89,14 @@ impl Frame {
  ///
  /// [`Path`]: path/struct.Path.html
  /// [`Frame`]: struct.Frame.html
  - pub fn fill(&mut self, path: &Path, fill: Fill) {
  + pub fn fill(&mut self, path: &Path, fill: impl Into<Fill>) {
  use lyon::tessellation::{
  BuffersBuilder, FillOptions, FillTessellator,
  };
  let mut buffers = BuffersBuilder::new(
  &mut self.buffers,
  - FillVertex(match fill {
  + FillVertex(match fill.into() {
  Fill::Color(color) => color.into_linear(),
  }),
  );
  