message: update shader param docs
diff: @@ -149,7 +149,7 @@ impl Canvas {
  /// Sets the shader parameters to use when drawing meshes.
  ///
  - /// **Bound to bind group 4.**
  + /// **Bound to bind group 3.**
  #[inline]
  pub fn set_shader_params<Uniforms: AsStd140>(&mut self, params: ShaderParams<Uniforms>) {
  self.state.params = Some((params.bind_group.clone(), params.layout));
  @@ -169,7 +169,7 @@ impl Canvas {
  /// Sets the shader parameters to use when drawing text.
  ///
  - /// **Bound to bind group 4.**
  + /// **Bound to bind group 3.**
  #[inline]
  pub fn set_text_shader_params<Uniforms: AsStd140>(&mut self, params: ShaderParams<Uniforms>) {
  self.state.text_params = Some((params.bind_group.clone(), params.layout));
  