Add missing labels to the `emotion` field description (#5)

- Add missing labels to the `emotion` field description (a9e143f05343428d53330ad64db415f9b059bd79)

README.md

@@ -139,8 +139,8 @@ The data fields are the same among all splits.
 
 #### default
 - `dialog`: a `list` of `string` features.
-- `act`: a `list` of classification labels, with possible values including `__dummy__` (0), `inform` (1), `question` (2), `directive` (3), `commissive` (4).
-- `emotion`: a `list` of classification labels, with possible values including `no emotion` (0), `anger` (1), `disgust` (2), `fear` (3), `happiness` (4).
+- `act`: a `list` of classification labels, with possible values including `__dummy__` (0), `inform` (1), `question` (2), `directive` (3) and `commissive` (4).
+- `emotion`: a `list` of classification labels, with possible values including `no emotion` (0), `anger` (1), `disgust` (2), `fear` (3), `happiness` (4), `sadness` (5) and `surprise` (6).
 
 ### Data Splits