Incorrect type of `LanguageDetail.keywords`

[alexeyinkin]

LanguageDetail.keywords are currently defined as

highlight.js/types/index.d.ts

Line 172 in cc93b0e

keywords?: Record<string, any> | string

But we have at least 3 formats:

1. Whitespace-separated string as in Cos.
2. string[] as in Dockerfile.
3. Record<string, string | string[]> (plus optional $pattern) as in Dart.

The 2nd one is illegal in that definition. And the 3rd one is not as specific as it can be.

Should the correct one be string | string[] | Record<string, string | string[]> ?

Same goes for ModeDetail.

Since we are here, must we really support that variety of definitions? Is there a performance difference in loading that? Or is there no reason to prefer whitespace-separated string over string[]? Could we change to something like Record<string, string[]> in version 12? (plus some provision for $pattern: string, not sure how to code that correctly).

The reason I care is that I am porting your package to Dart, and the porting script for diverse definitions is harder to maintain.

[joshgoebel]

string | string[] | Record<string, string | string[]>

Yes, I believe that was the intent. PR would be welcome.