Use different MIME type when creating s3 folders

#120

src/stores/s3objects.ts

@@ -297,7 +297,7 @@ export const useS3ObjectStore = defineStore({
       const command = new PutObjectCommand({
         Bucket: bucketName,
         Body: "",
-        ContentType: "text/plain",
+        ContentType: "application/octet-stream",
         Key: key,
       });
       return this.client.send(command).then(() => {