Missing CSS fix and A11y tweaks to achieve 4 Hundos

• Fixed missing CSS by moving PurgeCSS config from script to file
• Fixed aria-label issue on span tag by adding role="link"; should result in 4 perfect scores (100s) on Lighthouse report

Eleventy v1 version of site

• Upgrade core SSG engine to https://github.com/11ty/eleventy/releases/tag/v1.0.2
• Update all npm packages (it's been over 2 years and it was long overdue)

Eleventy v0.11 version of site

v3.1.0

Merge pull request #148 from austinjavascript/dependabot/npm_and_yarn…