Update chain configuration overview page

Author: richardgreg

pages/builders/chain-operators/configuration/overview.mdx

@@ -18,6 +18,10 @@ documentation for details on configuring each piece.
 
   Deploying your OP Stack contracts requires creating a deployment configuration
   JSON file. This defines the behavior of your network at its genesis.
+  *   **Important Notes:**
+      *   The Rollup Configuration sets parameters for the L1 smart contracts upon deployment. These parameters govern the behavior of your chain and are critical to its operation.
+      *   Be aware that many of these values cannot be changed after deployment or require a complex process to update.
+          Carefully consider and validate all settings during configuration to avoid issues later.
 
   *   [Rollup Configuration Documentation](/builders/chain-operators/configuration/rollup)