chore: node 20, mv components directory src to root, add emulsify-cor…

[joetower]

…e as only dependency

Summary

This PR fixes/implements the following bugs/features

• Upgrades the .nvmrc file to node 20
• Includes emulsify-core as the only dependency - aside from ui-kit-specific dev dependencies
• Makes the sass structure modular, using @use and @forward instead of @import
• Moves components directory to the root from src/components - the cli expects components to live in the root
• Updates images directory name to assets

Explain the motivation for making this change. What existing problem does the pull request solve?

Documentation update (required)

If this pull request requires a change to Emulsify documentation, those changes, updates, and/or new information must accompany this pull request.

How to review this pull request

• Checkout branch
• Remove your node_modules directory - rm -rf node_modules
• Run npm install
• Run npm run develop and make sure Storybook runs properly
• Cancel and run npm run build and make sure everything builds as it should

Closing issues

Closes #