feat(Demo) - Navigation aware sidebar

[devfreddy]

Summary

The original design https://www.figma.com/proto/YAkXjlXfvOZaWaKtIEQynq/NR1-Community?node-id=1%3A1372&viewport=-306%2C237%2C0.8856343030929565&scaling=min-zoom calls for a sidebar navigation allowing for easier access to headers in the documentation.

Desired Behaviour

• A user is contextually aware based on the currently highlighted item in the sidebar navigation
• Clicking one of the items in the sidebar takes the user to that header in the documentation

Possible Solution

Assuming a similar structure to what we have currently we would need to:

• Define a set of headers/children for navigation items from the main body of example code
• Derive an aggregate of headers included in the README.md of the component
• Merge these two together into one navigation tree for the sidebar
• Add visibility awareness in the documentation to both
• Upon become visible or being clicked, navigate to the correct header

Currently we have some visibility awareness handler/callbacks for the Markdown headers.