Updates for version 3.0

Version 3.0 introduces breaking changes:

• Removed viewport component, this extra layer was redundant;
• Changed classes to complex names in order to support bootstrap and other libraries:
  • row -> rgRow;
  • col -> rgCol;
  • data-cell -> rgCell;
  • data-header-cell -> rgHeaderCell;
• All methods migrated to lowercase in order to support the modern approach of event naming. It means events name migration: afterEdit -> afteredit for all events. Check api for details;
• Added pure esm modules support in order to use the grid in all modern frontend tooling like vitejs, parcel etc, now you can import custom-elements without lazy loading, just keep in mind you are responsible for polifills.