feat(Navigation): Move contributing content
Move the contributing content to a more appropriate location under Get started.
This is a positive change in that:
- This key content is no longer buried under the last navigation items.
- The Get started section is now more robust with both contributing and component lifecycle content — both of which are helpful as you get started.
- The navigation is now 3 lines shorter.
While it's true that the links were exposed before, and are now behind a toggle, I think it's still a net positive to have them under a more appropriate nav category and nearer to the top of the menu.
Closes #1045 (closed)
Edited by Jeremy Elder