Fix langs TS typing

[reda-alaoui]

No description provided.

[reda-alaoui]

Hello? This looks so easy to merge 🙏

[Balearica]

Can you explain this change?

[reda-alaoui]

@Balearica as you can see in:

tesseract.js/src/worker-script/index.js

Line 139 in bdf76b8

await Promise.all((typeof langs === 'string' ? langs.split('+') : langs).map(loadAndGunzipFile));

and

tesseract.js/src/worker-script/index.js

Line 77 in bdf76b8

const lang = typeof _lang === 'string' ? _lang : _lang.code;

index.d.ts is incomplete about lang typing.