Added ability to pass in dictionary schema

Author: dhanshew72

libs/weaviate/langchain_weaviate/vectorstores.py

@@ -91,6 +91,7 @@ def __init__(
         index_name: Optional[str],
         text_key: str,
         embedding: Optional[Embeddings] = None,
+        schema: Optional[dict] = None,
         attributes: Optional[List[str]] = None,
         relevance_score_fn: Optional[
             Callable[[float], float]
@@ -113,12 +114,15 @@ def __init__(
         if attributes is not None:
             self._query_attrs.extend(attributes)
 
-        schema = _default_schema(self._index_name)
-        schema["MultiTenancyConfig"] = {"enabled": use_multi_tenancy}
+        if not schema:
+            self.schema = _default_schema(self._index_name)
+            schema["MultiTenancyConfig"] = {"enabled": use_multi_tenancy}
+        else:
+            self.schema = schema
 
         # check whether the index already exists
         if not client.collections.exists(self._index_name):
-            client.collections.create_from_dict(schema)
+            client.collections.create_from_dict(self.schema)
 
         # store collection for convenience
         # this does not actually send a request to weaviate