4.0.0

What's Changed

• Update of web-component version to 3.0.0 to get new features:
  • fix to arrow keys navigation: was not working when navigation reached hidden buttons.
  • make each toolbar standard button to include a slot for the icon, so icons can be replaced easily if wanted with a new Icon.
• New API for Icon replacement of toolbar standard buttons.
• Version has been upgraded to 4.0.0 as changes in web-component are considered breaking as they include styling changes that might affect styling applied to buttons.

by @paodb in #30

Full Changelog: 3.0.1...4.0.0