Address review feedback

Author: deepika-awasthi

custom_worker_tuner/README.md

@@ -4,6 +4,8 @@ A `CustomSlotSupplier` is a sample that lets you gate slot grants on whatever yo
 This sample gates on a fake DB pool: the worker only polls for a new
 activity when the pool has a free connection.
 
+**Note:** This sample is illustrative only. It shouldn't be used for production grade use-cases.
+
 ## What this sample is
 db_pool.py - A static-capacity counter. Pretends to be a DB pool. Two methods: increment() (claim a slot, returns False if full), decrement() (release)
 supplier.py - The custom slot supplier. On reserve_slot it polls downstream.increment() until it succeeds. On release_slot it calls downstream.decrement()