Clean up website build

[Josmithr]

Primary changes:

• Add separate script for building just the website contents, and not doing things like running md-magic on non-website contents.
• Update scripts to use npm-run-all instead of concurrently
• Update js scripts to use chalk instead of colors
• Update generated script content in docs README

[tylerbutler]

Love it! The only thing I'm conflicted about is npm-run-all. I'm not opposed to switching, but I think we should do it everywhere at one time rather than piecemeal.

[github-actions]

🔗 Found some broken links! 💔

Run a link check locally to find them. See
https://github.com/microsoft/FluidFramework/wiki/Checking-for-broken-links-in-the-documentation for more information.

linkcheck output

> fluidframework-docs@0.25.0 linkcheck /home/runner/work/FluidFramework/FluidFramework/docs
> npm run linkcheck:fast -- --external


> fluidframework-docs@0.25.0 linkcheck:fast /home/runner/work/FluidFramework/FluidFramework/docs
> linkcheck http://localhost:1313 --skip-file skipped-urls.txt "--external"

Crawling...

http://localhost:1313/css/style.min.f22f6c22fcc37a0d857a17c9c1202a67c28deef90cc26a52b7539b903f623331.css
- (1:583) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/light/latest.eot? (HTTP 503)
- (1:1031) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/light/latest.svg (HTTP 503)
- (1:1184) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/semilight/latest.eot (HTTP 503)
- (1:1272) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/semilight/latest.eot? (HTTP 503)
- (1:1634) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/semilight/latest.ttf (HTTP 503)
- (1:1740) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/semilight/latest.svg (HTTP 503)
- (1:1897) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/normal/latest.eot (HTTP 503)
- (1:1982) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/normal/latest.eot? (HTTP 503)
- (1:2427) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/normal/latest.svg (HTTP 503)
- (1:2668) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/semibold/latest.eot? (HTTP 503)
- (1:3025) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/semibold/latest.ttf (HTTP 503)
- (1:3130) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/semibold/latest.svg (HTTP 503)
- (1:3286) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/bold/latest.eot (HTTP 503)
- (1:3369) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/bold/latest.eot? (HTTP 503)
- (1:3811) url(...) => https://c.s-microsoft.com/static/fonts/segoe-ui/west-european/bold/latest.svg (HTTP 503)

http://localhost:1313/docs/apis/core-interfaces/ifluidcodedetailscomparer
- (873:360) 'Array.sort' => https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort#Description (HTTP 200 but missing anchor)
- (877:168) 'https://..' => https://github.com/npm/node-semver#usage (HTTP 200 but missing anchor)
- (885:25) 'Array.sort' => https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort#Description (HTTP 200 but missing anchor)
- (914:25) 'https://..' => https://github.com/npm/node-semver#usage (HTTP 200 but missing anchor)

http://localhost:1313/docs/apis/core-interfaces/ifluidcodedetailscomparer/
- (873:360) 'Array.sort' => https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort#Description (HTTP 200 but missing anchor)
- (877:168) 'https://..' => https://github.com/npm/node-semver#usage (HTTP 200 but missing anchor)
- (885:25) 'Array.sort' => https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort#Description (HTTP 200 but missing anchor)
- (914:25) 'https://..' => https://github.com/npm/node-semver#usage (HTTP 200 but missing anchor)


Stats:
  121051 links
    1316 destination URLs
       1 URLs ignored
       8 warnings
      15 errors

[github-actions]

This commit is queued for merging with the next branch! Please ignore this PR for now. Contact @microsoft/fluid-cr-infra for help.