CLI reference documentation

[andreasjansson]

Cog has reference documentation for the Python API but no reference for the command line interface. The tutorials explain parts of the CLI, but it would be great to have a single page listing all of Cog's commands and their arguments.

Topics to cover:

• How to run the HTTP server
• Inspecting the generated dockerfile with cog debug dockerfile
• Using the --debug flag for move verbose output
• cog push returns Docker image id (aka model version id) as last line of STDOUT (see Output image ID at end of build/push #804)
• cog debug -- see Document cog debug command #1349

(edited by @zeke)

[zeke]

The CLI docs should probably also explain how to run the HTTP server: #413 (comment)

[zeke]

Should probably also document $ cog debug dockerfile here too.