remove errorneous dataset

ROTTERDAM/data-00000-of-00001.arrow

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:2c35a723f5fa9d38fd502e5cc964f9bc850320e2e22d51eee00f979b8de6dc90
-size 19260264

ROTTERDAM/dataset_info.json

@@ -1,48 +0,0 @@
-{
-  "builder_name": "generator",
-  "citation": "",
-  "config_name": "default",
-  "dataset_name": "ROTTERDAM",
-  "dataset_size": 19259234,
-  "description": "",
-  "download_checksums": {},
-  "download_size": 0,
-  "features": {
-    "item_id": {
-      "dtype": "string",
-      "_type": "Value"
-    },
-    "start": {
-      "dtype": "timestamp[s]",
-      "_type": "Value"
-    },
-    "freq": {
-      "dtype": "string",
-      "_type": "Value"
-    },
-    "target": {
-      "feature": {
-        "dtype": "float32",
-        "_type": "Value"
-      },
-      "_type": "Sequence"
-    }
-  },
-  "homepage": "",
-  "license": "",
-  "size_in_bytes": 19259234,
-  "splits": {
-    "train": {
-      "name": "train",
-      "num_bytes": 19259234,
-      "num_examples": 208,
-      "dataset_name": "generator"
-    }
-  },
-  "version": {
-    "version_str": "0.0.0",
-    "major": 0,
-    "minor": 0,
-    "patch": 0
-  }
-}

ROTTERDAM/state.json

@@ -1,13 +0,0 @@
-{
-  "_data_files": [
-    {
-      "filename": "data-00000-of-00001.arrow"
-    }
-  ],
-  "_fingerprint": "a94aac3aab4ebed5",
-  "_format_columns": null,
-  "_format_kwargs": {},
-  "_format_type": null,
-  "_output_all_columns": false,
-  "_split": "train"
-}