adding to breadcrumbs file

Author: sbvegan

pages/operators/chain-operators/tools.mdx

@@ -16,6 +16,7 @@ This section provides information on chain monitoring options, deploying a block
   <Card title="Chain monitoring options" href="/operators/chain-operators/tools/chain-monitoring" />
   <Card title="Fjord fee parameter calculator" href="/operators/chain-operators/tools/fee-calculator" />
   <Card title="Deploying a block explorer" href="/operators/chain-operators/tools/explorer" />
+  <Card title="Validating a Standard OP Stack chain" href="/operators/chain-operators/tools/op-validator" />
   <Card title="How to configure challenger for your chain" href="/operators/chain-operators/tools/op-challenger" />
   <Card title="Conductor" href="/operators/chain-operators/tools/op-conductor" />