feat: fp-1499 ui pattern demo

[wesleyboar]

Overview

Add npm start command to demo core-styles patterns (using Fractal).

This demo lets us prove CSS modules work before a client* uses them.

_{* Clients are core-components, Core-CMS, Core-Portal, and future external parties.}

To Do

• no italics for button icons — 474eff3

Related

• TUP-1499
• required by task/FP-1499: CMS pattern library Core-CMS#512
  required by Task/fp 1499 ui pattern demo Core-CMS#527
• mimics Task/fp 1499 core-styles pattern demo tup-ui#28
• replaces Task/fp 1499 core-styles demo tup-ui#45

Changes

• .gitignore demo output
• docs: fractal usage hints, demo homepage
• configure fractal (and customize its theme)
• split build script into build:css and build:demo
• support different ways to load stylesheets
• change c-button demo code from KSS to Fractal
• install Fractal dependencies in root

Testing

1. npm ci

2. npm run build:css

3. npm run start

4. UI of patterns in demo match Portal UI for the same pattern.﹡

5. (bonus) Test CMS UI Demo.†

   • instructions: see Task/fp 1499 ui pattern demo Core-CMS#527
   • branch: task/fp-1499-ui-pattern-demo--fp-1726-publications-list

^{﹡ See screenshots in "UI" section.
† The CMS (or any client) can apply its styles atop the core-styles demo.}

UI

primary	secondary	tertiary	small

Fixes

no italics for pseudo-icons (474eff3)

[wesleyboar]

Retiring this repo in favor of https://github.com/TACC/tup-ui.