Scaffold @wpengine/hwp-template-hierarchy NPM package

[josephfusco]

Acceptance Criteria

• WordPress posts and pages can be rendered in a predictable way
• Package is framework agnostic
• Utilizes the existing Template Hierarchy work in Faust.

Note

This relates to our roadmap - Begin focused development on @wpengine/hwp-template-hierarchy and @wpengine/hwp-auth packages - https://github.com/wpengine/faustjs/blob/canary/ROADMAP.md