Update CLI runner documentation

[josephmckinsey]

• Adds mkdocs-click to the pyproject.toml docs dependencies
• Uses mkdocs-click to display autogenereated helics CLI documentation, and removes the old copy-pasted --help commands.
• Adds more content to the helics run CLI doc-string and argument help strings.

You should be able to see the changes if you do mkdocs serve and go to the CLI interface section. You can also see the updated documentation at helics run --help.