1.3     2020/06/27
- added otptool which knows only otpauth:// links

1.2     2020/06/27
- added support for custom character classes
- added compatibility with Steam Guard

1.1     2020/06/27
- added support for parsing otpauth://... links
- added compatibility with Google Authenticator

1.0     2020/06/27
- added support for HOTP
- added support for TOTP
