[npm diff] diff command is missing

[nikolaischunk]

Sanity checks

• My issue relates to a specific CLI completion spec (e.g. git checkout is missing options in git completion spec). If your issue is more general, please create your issue here: withfig/fig
• I have searched github.com/withfig/autocomplete/issues and there are no duplicates of my issue
• I would like to work on this.

What CLI tool does this relate to?

npm

Which statement makes the most sense?

This completion spec isn't complete

Issue Details

When previewing npm diff, nothing comes up.
I checked the sourcecode of the npm spec, and see no mention of diff.
Source to the npm diff command: https://docs.npmjs.com/cli/v10/commands/npm-diff