Update metrics.md (#863)

Author: rafrombrc

src/cookbooks/metrics.md

@@ -1,5 +1,5 @@
 # Metrics
 
-The most accurate and up-to-date metric information can be found on the [Metrics Inventory](https://mozilla-hub.atlassian.net/wiki/spaces/DATA/pages/620494911/Metrics+Inventory) page in Confluence (Mozilla LDAP required).
+The most accurate and up-to-date metric information can be found in the DataHub data catalog's [Metrics Glossary](https://mozilla.acryl.io/glossaryNode/urn:li:glossaryNode:Metric%20Hub/Contents?is_lineage_mode=false) (Mozilla LDAP required).
 
-The official source code definitions for the metrics can be found in [metric-hub](https://github.com/mozilla/metric-hub/tree/main/definitions) in GitHub.
+The official source code definitions for the metrics can be found in [metric-hub](https://github.com/mozilla/metric-hub/tree/main/definitions) in GitHub. Documentation describing how to create and use metric-hub metrics is available [elsewhere on this site](https://docs.telemetry.mozilla.org/concepts/metric_hub).