add notes

resource/ckb.toml

@@ -131,6 +131,11 @@ enable_deprecated_rpc = false # {{
 # integration => enable_deprecated_rpc = true
 # }}
 
+# By default, there is not limitation on the size of batch request size
+# a huge batch request may cost a lot of memory or makes the RPC server slow,
+# to avoid this, you may want to add a limit for the batch request size.
+# rpc_batch_limit = 2000
+
 [tx_pool]
 max_tx_pool_size = 180_000_000 # 180mb
 min_fee_rate = 1_000 # Here fee_rate are calculated directly using size in units of shannons/KB