fix: update resource cache for Hugo 0.100

fix: can not use cached resources

Closes wangchucheng#193

chore: update dependencies

refactor: upgrade to Tailwind CSS v3

fix: purge css resources

refactor: remove showcase link in README

docs: update demo url

fix: cannot switch color scheme without utterances

feat: recursive repoEditURL

BREAKING CHANGES: Param 'repoURL' in params.yaml is deprecated.

chore: upgrade to tailwindcss 2.0

Closes wangchucheng#78