Create template for writing page template guidance

[SmartMouthWords]

Create template for the team to use to write documentation for GC Design System's page templates.

To do

• [x]  Document page template page elements and instructions
• [x]  Explore format
• [x]  Produce prototype

Outcomes

• Make it easier for team members to contribute design system documentation

Deliverables

• Prototype template for page templates

[SmartMouthWords]

Started template draft based on the basic page template structure so far.

[SmartMouthWords]

Template draft complete. Needs review/team feedback, especially @MatildePerrusclet and @realdylanzheng