Random seed in --help output

[svenkevs]

Not a big issue, very minor actually.

When running the --help argument (swift run StableDiffusionSample --help) the generated documentation calculates a random seed each time, and passes the result of the RNG as the default seed option.

The documentation implies that you have to provide some argument with --seed in order to get a random number, or otherwise it will provide the shown 'default value'. While this should be the other way around.

Run 1:
--seed Random seed (default: 3944433010)
Run 2:
--seed Random seed (default: 1029080931)
Run n:
--seed Random seed (default: 769278928)

[svenkevs]

Made a pull request for a small improvement on the help output: #221