iperf manpage missing

[Profpatsch]

Issue description

iperf has a manpage according to https://linux.die.net/man/1/iperf, but it’s not in the nix package.

Steps to reproduce

nix-shell -p iperf --run 'man iperf'

cc @fpletz as maintainer.

[marsam]

I think the manpage is iperf3

🗁  dspc1mcc53n928gvcghcjk97rk98ifx1-iperf-3.6
├── 🗁  bin
│  ├── 🗋  iperf
│  └── 🗋  iperf3
├── 🗁  include
│  └── 🗋  iperf_api.h
├── 🗁  lib
│  ├── 🗋  libiperf.la
│  ├── 🗋  libiperf.so
│  ├── 🗋  libiperf.so.0
│  └── 🗋  libiperf.so.0.0.0
└── 🗁  share
   └── 🗁  man
      ├── 🗁  man1
      │  └── 🗋  iperf3.1.gz
      └── 🗁  man3
         └── 🗋  libiperf.3.gz

[Profpatsch]

Should we create a symlink?