page/page.go
func (p PrintToPDFParams) WithMarginTop(marginTop float64) *PrintToPDFParams {
	p.MarginTop = marginTop
	return &p
}
func (p PrintToPDFParams) WithMarginTop(marginTop float64) *PrintToPDFParams {
	p.MarginTop = marginTop
	return &p
}
// WithMarginTop top margin in inches. Defaults to 1cm (~0.4 inches).