Documentation update: Divider (formerly known as horizontal rules)

[caw310]

Make updates to Divider (formerly Horizontal rules ) on design.va.gov, Storybook and Sketch library to fix the discrepancies that have been identified.

Tasks

• Add Divider to design.va.gov with user guidance
• Add View guidance for the Horizontal rules component in the Design System
• Add a link in Storybook that links back to Horizontal rules on design.va.gov (See example on va-modal)
• Update link to Storybook on design.va.gov to "View Divider in Storybook"
• Update Sketch file with Horizontal rule/Stars component

Acceptance Criteria

• Divider has a component on design.va.gov with guidance on usage
• Storybook has link “View guidance for the Divider component in the Design System”
• Storybook has a link to the component page on design.va.gov
• Divider link to Storybook is labeled "View Divider in Storybook"
• Sketch file has Divider component

[humancompanion-usds]

I think the guidance we have for Divider is adequate. I've updated the initial comment on this issue to reflect what we've done and what work remains. @GnatalieH let me know that we'll need to recreate the stars divider in Sketch as we don't have it.