feat(marketing): Implement chart creation step

This commit introduces the second step in the marketing page's stepper, which allows users to create a chart. The previous placeholder content has been replaced with the new `ChartStep` component.

To support form functionality within this new step, the `Button` component has been updated to accept a `type` attribute (`button`, `submit`, `reset`), enabling proper form submission handling.

src/components/ui-elements/button.tsx

@@ -37,6 +37,7 @@ type ButtonProps = HTMLAttributes<HTMLButtonElement> &
   VariantProps<typeof buttonVariants> & {
     label: string;
     icon?: React.ReactNode;
+    type?: "button" | "submit" | "reset";
   };
 
 export function Button({