v2.6.0-rc.1

Changelog

🎉 Restore compatiblity with Firefox 🦊

• Upgrade Asciidoctor.js from 2.1.1 to 2.2.0
• Upgrade Asciidoctor Kroki from 0.7.0 to 0.8.1
• Support sidebar toc
• Compatibility with Firefox, use the same code base again!
• Remove chartist sourcemap reference
• Update development dependencies
  • Bump mocha from 7.1.1 to 7.2.0
  • Bump puppeteer from 2.1.1 to 3.1.0
  • Bump standard from 14.3.3 to 14.3.4
  • Bump node-sass from 4.14.0 to 4.14.1
  • Bump archiver from 3.1.1 to 4.0.1
  • Bump addons-linter from 1.23.0 to 1.24.0