Adding Debian manpage to python-slugify

[Arian-Ott]

Hi,

I’m maintaining the Debian package for python-slugify, which currently includes an old manpage (slugify.1) for the CLI tool. Inside the manpage you'd want to document the python-slugify CLI for CLI users.

Since it could be useful to other users as well, I wanted to forward it upstream in case you’d be interested in including it.

If you’re open to it, I’m happy to send a PR with the manpage added. You can place it either in a dedicated man/ directory or just leave it in the root directory.

Best,
Arian