Harrison/chroma update (#3489)

Co-authored-by: vyeevani <30946190+vyeevani@users.noreply.github.com>
Co-authored-by: Vineeth Yeevani <vineeth.yeevani@gmail.com>

langchain/vectorstores/chroma.py

@@ -315,6 +315,17 @@ class Chroma(VectorStore):
             )
         self._client.persist()
 
+    def update_document(self, document_id: str, document: Document) -> None:
+        """Update a document in the collection.
+
+        Args:
+            document_id (str): ID of the document to update.
+            document (Document): Document to update.
+        """
+        text = document.page_content
+        metadata = document.metadata
+        self._collection.update_document(document_id, text, metadata)
+
     @classmethod
     def from_texts(
         cls: Type[Chroma],