docs: clean up docstring (merged content from README.md)

Author: aaronsteers

airbyte_cdk/test/models/connector_metadata/__init__.py

@@ -1,4 +1,15 @@
-"""Connector metadata models for validation and testing.
+"""Pydantic and JSON Schema models for `metadata.yaml` validation and testing.
+
+## Usage
+
+```python
+from airbyte_cdk.test.models import ConnectorMetadataDefinitionV0
+import yaml
+
+metadata = ConnectorMetadataDefinitionV0(**yaml.safe_load(metadata_yaml))
+```
+
+## Regenerating Models
 
 These models are auto-generated from JSON schemas in the airbytehq/airbyte repository.
 For information on regenerating these models, see the Contributing Guide: