Adds stakeholders section pages

[brentryanjohnson]

• Adds three pages in stakeholders section

Warning
Previews won't work, since we don't yet have a [...slug].astro page for this section (or for the how-it-works section)

Note
One of page titles in Figma ("Agency/Organization Program Coordinators (A/OPCs) Responsibilities" differs from that of the corresponding google doc ("Program Coordinator Responsibilities"). Also in Figma, the side nav title ("A/OPC Responsibilities") is different than the page title. To my knowledge, the engineers pull the page title for use in the side nav, and I don't think we currently have a way to use a side nav title that's different from the corresponding page title.

Note
So far, we've assumed a landing page for each section (index.md). This page uses "Key Players" for the landing page, which would render at the path /stakeholders/ instead of /stakeholders/key-players/

[mark-meyer]

@brentryanjohnson do you want to merge this in, or wait until we do some dev work to make it live?

[brentryanjohnson]

@mark-meyer I think we can merge it so the branch doesn't get stale. Should we add issues for the Astro pages we need?