Function render 

pub fn render<F: Function + RenderHints>(
    b: BoundShape<'_, F, f32>,
    render_config: &RenderConfig,
    eval_config: &EvalConfig<'_>,
) -> Option<Image>

Renders a shape into a 2D image, with the provided configuration

The shape provides the evaluator backend (F) and bound variables; the configuration supplies resolution, transforms, etc.

Returns Some(Image) of pixel data if rendering succeeds, or None if rendering was cancelled (using the EvalConfig::cancel.