Add CLI option for raw text mode (no colors at all).

[mk-pmb]

To simplify using this client in scripts, I'd like a raw text mode that avoids all terminal control codes (color, cursor positioning, not sure what else).
Raw text mode would thus include disabling markdown rendering.
I found the markdown option, but even with that disabled, the model name and separator line are still in color.
Also I'd like a CLI option for raw text mode.
Also raw text mode shall be the default if standard output is not a TTY. (Even better if we can check termcap for color code support, but that's probably a feature that should be implemented upstream in Rich.)
Also raw text mode shall be the default if using the dumb terminal (environment variable TERM is set to dumb).

[monperrus]

You can pipe into ansi2txt from package colorized-logs

apt install colorized-logs

[mk-pmb]

Thanks for the idea! Indeed I had considered using sed to stip all terminal control codes from the output and the excess newlines after the input prompt. Nonetheless, I think all of the features requested above should be in chatgpt-cli.