In project A, there is some configuration?, which makes TS detect type files. By types file, I mean a file that includes just TS types without exporting or importing anything, it doesn’t have .d.ts extension, just simple .ts extension. And everywhere in the vscode project, I can use the types defined in type files without importing them.

How can I replicate this behaviour in Project B, what is the configuration that makes this magical TS type definition detection works without export/import?