[Component pages] Re-order tabs and add demo to usage

[aagonzales]

Part 1

Re-order the tabs on the component page in below following order. This should be done to all component page at once.

1. Usage
2. Style
3. Code
4. Accessibility

Part 2

Add the component demo to the usage tab. It should go under the anchor links and before the overview section. There is a caption that should be added under each demo, "Interactive demo for the x component." This should be done to all component pages at once.

Spacing: 48px between anchor links and demo, 80px between demo caption and overview section.

Part 3

The demo should remain on the code tab as well until there are new dev docs ready to be added to that tab. Then the demo can be removed on the code tab in favor of in-context demos. This part can be done piecemeal.