FLEET-19 Add CHANGELOG Entry

.changesets/feat_jr_add_fleet_awareness_plugin.md

@@ -0,0 +1,11 @@
+### Adds Fleet Awareness Plugin
+
+Adds a new plugin that reports telemetry to Apollo on the configuration and deployment of the Router. Initially only
+reports, memory and CPU usage but will be expanded to cover other non-intrusive measures in future. 🚀
+
+As part of the above PluginPrivate has been extended with a new `activate` hook which is guaranteed to be called once
+the OTEL meter has been refreshed. This ensures that code, particularly that concerned with gauges, will survive a hot
+reload of the router.
+
+By [@jonathanrainer](https://github.com/jonathanrainer), [@nmoutschen](https://github.com/nmoutschen), [@loshz](https://github.com/loshz)
+in https://github.com/apollographql/router/pull/6151