[Feature] add ability to manage past board members listing page, similar to `team-index` context.

## Problem
The[ board listing page](https://creativecommons.org/mission/team/board-members/) originally was a table edited through the `TablePress` plugin. This is not ideal, and it did not migrate fully into the new site. To resolve this, post migration, a table was inserted into the page manually, and is currently edited manually in the same fashion.

Some form of GUI based editing would be more user-friendly.

## Description
If we follow a similar functionality route to the `team-index` context we might be able to accommodate this more easily. However, there are other dimensions of data that are present on that page that are not captured within a Person content type post.

Once the presentational UX is resolved here, this can migrate to an adjoining Issue within `vocabulary-theme` to work out the backend implementation details and modelling.

## Alternatives
Rebuild the table within Tablepress, improving the manageability, but not making it match other routes of "person listing" management.

## Implementation

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