Remove misleading warning about Document node not being created (#218)

* Remove misleading warning

* Update message

Author: stellasia

examples/build_graph/simple_kg_builder_from_text.py

@@ -3,6 +3,8 @@
 
 This example assumes a Neo4j db is up and running. Update the credentials below
 if needed.
+
+NB: when building a KG from text, no 'Document' node is created in the Knowledge Graph.
 """
 
 import asyncio
@@ -21,7 +23,7 @@
 # Neo4j db infos
 URI = "neo4j://localhost:7687"
 AUTH = ("neo4j", "password")
-DATABASE = "newdb"
+DATABASE = "neo4j"
 
 # Text to process
 TEXT = """The son of Duke Leto Atreides and the Lady Jessica, Paul is the heir of House Atreides,

src/neo4j_graphrag/experimental/components/lexical_graph.py

@@ -13,7 +13,7 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 import asyncio
-import warnings
+import logging
 from typing import Any, Dict, Optional
 
 from pydantic import validate_call
@@ -30,6 +30,8 @@
 )
 from neo4j_graphrag.experimental.pipeline import Component
 
+logger = logging.getLogger(__name__)
+
 
 class LexicalGraphBuilder(Component):
     """Builds the lexical graph to be inserted into neo4j.
@@ -53,8 +55,9 @@ async def run(
         document_info: Optional[DocumentInfo] = None,
     ) -> GraphResult:
         if document_info is None:
-            warnings.warn(
-                "No document metadata provided, the document node won't be created in the lexical graph"
+            logger.info(
+                "Document node not created in the lexical graph "
+                "because no document metadata is provided"
             )
         graph = Neo4jGraph()
         document_id = None