Change author and contact info in manpage

[pupto-bismol]

Currently, the bottom of the manpage looks like this:

...

       --power-no-setsid
           Do not prefix power commands with setsid, which is used to  detach  it
           from current TTY.

       --kb-[command|sessions|power] [1-12]
           change  the  default F-key keybindings to access the command, sessions
           and power menus.

  AUTHORS
       Maintained by Antoine POPINEAU <antoine@popineau.eu>.

       Contributed  to  by   great   people   at   https://github.com/apognu/tui‐
       greet/graphs/contributors.

  DEVELOPMENT
       Issue    reporting   and   development   discussion   should   happen   at
       https://github.com/apognu/tuigreet.

  SEE ALSO
       greetd(1)

                                     1980-01-01                       tuigreet(1)
(END)

but, obviously this software is under new maintenance at a new repo. So, it should probably be updated. Currently it's being generated by scdoc if that helps, but I'm not experienced with it so I honestly don't know the specifics.

(also might be a good opportunity to get it to generate with the correct date for nix users if possible, instead of I'm assuming just letting scdoc pull from the file timestamp, which gets nix/store'd)