[npm] support private registry

[claneo]

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?

There is a bug with this completion spec

Issue Details

Currently npm autocomplete uses api.npms.io to search package

autocomplete/src/npm.ts

Lines 32 to 34 in 7922234

	const queryPackagesUrl = keywordParameter
	? `https://api.npms.io/v2/search?size=20&q=${searchTerm}${keywordParameter}`
	: `https://api.npms.io/v2/search/suggestions?q=${searchTerm}&size=20`;

and registry.npmjs.org to search package version

autocomplete/src/npm.ts

Line 48 in 7922234

`https://registry.npmjs.org/${searchTerm.slice(0, -1)}`,

Both api only support public npm registry.

My suggestion is to use npm --json search command for packages and npm --json info for versions.