Argon2 version (defaults to the most recent version, currently 13)

.SH COPYRIGHT
This manpage was written by \fBDaniel Kahn Gillmor\fR for the Debian
distribution (but may be used by others). It is released, like the
rest of this Argon2 implementation, under a dual license. You may use this work
under the terms of a Creative Commons CC0 1.0 License/Waiver or the Apache
Public License 2.0, at your option.
