Update README with label2id mapping

README.md

@@ -495,12 +495,30 @@ See the [AWS Open Data Registry entry for MultiCoNER](https://registry.opendata.
 * `PROD`: Product, i.e. consumer products
 * `CW`: Creative Work, i.e. movies/songs/book titles
 
+### Dataset Structure
+The dataset follows the IOB format of CoNLL. In particular, it uses the following label to ID mapping:
+```python
+
+{
+    "O": 0,
+    "B-PER": 1,
+    "I-PER": 2,
+    "B-LOC": 3,
+    "I-LOC": 4,
+    "B-CORP": 5,
+    "I-CORP": 6,
+    "B-GRP": 7,
+    "I-GRP": 8,
+    "B-PROD": 9,
+    "I-PROD": 10,
+    "B-CW": 11,
+    "I-CW": 12,
+}
+```
+
 ## Languages
 The MultiCoNER dataset consists of the following languages: Bangla, German, English, Spanish, Farsi, Hindi, Korean, Dutch, Russian, Turkish and Chinese.
 
-## Dataset Structure
-The dataset follows the IOB format of CoNLL.
-
 ## Usage
 ```python
 from datasets import load_dataset