Added monitoring

src/docs/infra/monitoring.md

@@ -1,6 +1,11 @@
 ---
-title: Monitoring (coming soon)
+title: Monitoring
 lang: en-US
 ---
 
-# {{ $frontmatter.title }}
+# {{ $frontmatter.title }}
+
+* [Optimism public dashboard](https://public-grafana.optimism.io/d/9hkhMxn7z/public-dashboard?orgId=1&refresh=5m)
+* [Etherscan dashboard](https://optimistic.etherscan.io/)
+* [Dune analytics](https://dune.xyz/browse) has multiple Optimism dashboards, and you can also
+  [create your own](https://docs.dune.xyz/#queries)