v1.0.0-beta.6

Enhancements

• Add methods for getting/setting castling rights (getCastlingRights, setCastlingRights) (@neofight78 - 7cb2d34)
• Ensure put/remove functions update ep square (@neofight78 - #398 )
• Make moveNumber accessible (@neofight78 - #399)
• Add support for both ESM and CommonJS environments (@jorgecasar - #406)