add fileResolve option

Author: KingSora

index.d.ts

@@ -50,6 +50,11 @@ declare interface Options {
 	Loader?: typeof Loader;
 
 	resolve?: (file: string) => string | Promise<string>;
+
+	fileResolve?: (
+		file: string,
+		importer: string
+	) => string | null | Promise<string | null>;
 }
 
 declare interface PostcssModulesPlugin {