docs(build): update instruction on building carbon-coponents style (#1874)
docs(build): update instruction on building carbon-coponents style (#1874)

Refs IBM/carbon-components#1754.
carbon-design-system/carbon-components,carbon-design-system/carbon-components,carbon-design-system/carbon-components-react,carbon-design-system/carbon-components-react,carbon-design-system/carbon-components,joshblack/carbon-components-react,joshblack/carbon-components-react