v6.0.0

• Enhanced wheel and touch events for better CLS metrics for Google Performance and SEO, with:
  • Passive events
  • Event throttling to better control zoom speed in those cases
  • New wheelZoomSpeed option to control that speed
• Changed button images to SVG for faster download, and added slight contrast shadow to make them visible in any background
• Removed support for Internet Explorer, reducing the size and complexity of the package.
• Updated npm dev packages to latest versions