fix incorrect config name and docstring

blurb.py

@@ -202,9 +202,10 @@ _BIGBIO_VERSION = "1.0.0"
 
 
 class BlurbDataset(datasets.GeneratorBasedBuilder):
-    """BIOSSES : Biomedical Semantic Similarity Estimation System"""
+    """Source splits for BLURB data (train/val/test) for easy access.
+    """
 
-    DEFAULT_CONFIG_NAME = "biosses_source"
+    DEFAULT_CONFIG_NAME = "bc5chem"
     SOURCE_VERSION = datasets.Version(_SOURCE_VERSION)
     BIGBIO_VERSION = datasets.Version(_BIGBIO_VERSION)