Update comment wording

Co-authored-by: Andrew Eisenberg <aeisenberg@github.com>

src/util.ts

@@ -770,7 +770,7 @@ export function doesDirectoryExist(dirPath: string): boolean {
 }
 
 /**
- * Returns a list of files in a given directory.
+ * Returns a recursive list of files in a given directory.
  */
 export function listFolder(dir: string): string[] {
   if (!doesDirectoryExist(dir)) {