Adds callout to Validators overview.mdx

Added callout to highlight the importance of the oracle price feeder, since experienced validators may not realize the importance of this.

pages/dev-validators/overview.mdx

@@ -1,3 +1,5 @@
+import { Callout } from "nextra/components";
+
 # What is a Validator
 Validators are responsible for committing new blocks to the blockchain through an automated voting process.A validator's stake is slashed if they become unavailable or sign blocks at the same height.
 
@@ -16,3 +18,6 @@ For fees and mints, the tokens are distributed in every block relative to the nu
 
 If validators double sign, are frequently offline, or do not participate in governance, their staked Sei (including the Sei of users that delegated to them) can be slashed. Penalties can vary depending on the severity of the violation.
 
+<Callout emoji="⚠️">
+The Sei blockchain incorporates a unique slashing parameter validators must be aware of. Please read [Oracle Price Feeder](./oracle-price-feeder) for details.
+</Callout>