[Functionality] resolve the use of a `home-narrative`,`home-index`, or `walkthrough-summary` for a homepage summary context

## Problem
Certain contexts within a site design have higher level of influential gravity that the rest of the design and/or design system needs to adequately account for. Usually those are full blog posts, standard subpages, and the homepage itself. Designs that adequately resolve these areas enable strong and more stable design systems.

At current, there is no standard context from which to build a site homepage. The only present design example exists within the Index Project and is referenced as both `home-index` and `home-narrative`.

## Description
This is due in large part to the hyper specific design created just for that project's homepage; however such a design should extend from a more general solution that is held within Vocabulary. This would allow that primary context to account for most of the expected functionality and features, then, as needed, implementations can build on top of or extend that context for their own localized needs.

This could strengthen the Index project's homepage design, while also providing a stable route to do the same for other projects utilizing Vocabulary.

## Implementation

- [x] I would be interested in implementing this feature.