Feature request: NO_COLOR standard implementation

Nobody has claimed this yet.

Hi,

it would be great implement the NO_COLOR standard on **lsd** since there's many CLI already with it and save the users from use "color=never", "--monochrome-color" or whatever.
```
Command-line software which adds ANSI color to its output by default should check
for a NO_COLOR environment variable that, when present and not an empty string
(regardless of its value), prevents the addition of ANSI color.

By adopting this standard, users that prefer to have plain, non-colored text output
can export NO_COLOR=1 to their shell’s environment and automatically disable color
by default in all supported software.

If your software outputs color by default, please consider not doing so.

More info on: `https://no-color.org/`
```

Cheers

Start by reading the NO_COLOR specification linked in the issue and tracing lsd's existing color-option handling. Implement the standard behavior so a present, non-empty NO_COLOR variable disables ANSI color output, then verify that existing color controls still work and that NO_COLOR=1 produces plain output.

Written by the indexing model from the issue text.