[skip ci] Add comments to the file query_node.yaml (#7707)

Signed-off-by: NBennu <yunmei.li@zilliz.com>

configs/advanced/query_node.yaml

@@ -11,12 +11,12 @@
 
 queryNode:
   stats:
-    publishInterval: 1000 # milliseconds
+    publishInterval: 1000 # Interval for querynode to report node information (milliseconds)
 
   dataSync:
     flowGraph:
-      maxQueueLength: 1024
-      maxParallelism: 1024
+      maxQueueLength: 1024 # Maximum length of task queue in flowgraph
+      maxParallelism: 1024 # Maximum number of tasks executed in parallel in the flowgraph
 
   msgStream:
     search: