fix: use '_id' instead of 'id' in readme example

Author: Kornel-Toth

test/examples/src/create_db_and_doc.py

@@ -40,10 +40,10 @@
 # 3. Create a document ================================================
 # Create a document object with "example" id
 example_doc_id = "example"
-# Setting `id` for the document is optional when "post_document"
-# function is used for CREATE. When `id` is not provided the server
+# Setting `_id` for the document is optional when "post_document"
+# function is used for CREATE. When `_id` is not provided the server
 # will generate one for your document.
-example_document: Document = Document(id=example_doc_id)
+example_document: Document = Document(_id=example_doc_id)
 
 # Add "name" and "joined" fields to the document
 example_document.name = "Bob Smith"