Fix usage part in README

README.md

@@ -86,14 +86,16 @@ then, from within python load the datasets library.
     >>> from datasets import load_dataset, Features, Value
 
 Specifiy column types to prevent pyarrow error.
-    >>> features = Features({
-          "Type": Value("string"),
-          "DatasetName": Value("string"),
-          "AID": Value("int64"),     
-          "ID": Value("string"),
-          "IDType": Value("string"),
-          "SMILES": Value("string")
-        })
+```python
+features = Features({
+    "Type": Value("string"),
+    "DatasetName": Value("string"),
+    "AID": Value("int64"),
+    "ID": Value("string"),
+    "IDType": Value("string"),
+    "SMILES": Value("string")
+})
+
 
 Now load one of the 'ChAFF' datasets, e.g.,