v2.1.0

• Added cancel toggle function (PR 77):
  • function:
    • cancelToggle: (index) {} (return type - Future<bool>)
• Added these options PR 74):
  • center text:
    • centerText (optional, type bool - default false)
  • multi-line text:
    • multiLineText (optional, type bool - default false)
  • inherit activeFgColor and inactiveFgColor in customTextStyles
• Null safety improvements (PR 68)