Method spacing

src/components/stack.rs:35–39

(mut self, spacing: f32)

    }

    pub fn spacing(mut self, spacing: f32) -> Self {
        self.spacing = spacing;
        self.recalculate_layout();
        self
    }

    pub fn child<C: Component + 'static>(mut self, child: C) -> Self {
        self.children.push(Box::new(child));