Update file types and add note (vercel#559)

app/(chat)/api/files/upload/route.ts

@@ -11,13 +11,10 @@ const FileSchema = z.object({
     .refine((file) => file.size <= 5 * 1024 * 1024, {
       message: 'File size should be less than 5MB',
     })
-    .refine(
-      (file) =>
-        ['image/jpeg', 'image/png', 'application/pdf'].includes(file.type),
-      {
-        message: 'File type should be JPEG, PNG, or PDF',
-      },
-    ),
+    // Update the file type based on the kind of files you want to accept
+    .refine((file) => ['image/jpeg', 'image/png'].includes(file.type), {
+      message: 'File type should be JPEG or PNG',
+    }),
 });
 
 export async function POST(request: Request) {