fix: indicate this is ES Module and not transpiled to Common JS (#17)

package.json

@@ -4,6 +4,7 @@
 	"description": "Library for getting manipulating colors",
 	"main": "dist/index.js",
 	"types": "dist/types/index.d.ts",
+	"type": "module",
 	"scripts": {
 		"prepublishOnly": "cross-env NODE_ENV=production npm run build",
 		"build": "rimraf dist && tsc -p tsconfig.json && npm run build:types",