Clarify train_path and dev_path format (see [ci skip]
@@ -186,8 +186,8 @@ $ python -m spacy train [lang] [output_path] [train_path] [dev_path]
| ----------------------------------------------------- | ------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `lang` | positional | Model language. |
| `output_path` | positional | Directory to store model in. Will be created if it doesn't exist. |
-| `train_path` | positional | Location of JSON-formatted training data. |
-| `dev_path` | positional | Location of JSON-formatted development data for evaluation. |
+| `train_path` | positional | Location of JSON-formatted training data. Can be a file or a directory of files. |
+| `dev_path` | positional | Location of JSON-formatted development data for evaluation. Can be a file or a directory of files. |
| `--base-model`, `-b` | option | Optional name of base model to update. Can be any loadable spaCy model. |
| `--pipeline`, `-p` <Tag variant="new">2.1</Tag> | option | Comma-separated names of pipeline components to train. Defaults to `'tagger,parser,ner'`. |
| `--vectors`, `-v` | option | Model to load vectors from. |
