Update CHANGES.md for v18.9.1 release
+## v18.9.1
+
+* Web UI
+ * **New** Default landing page provides namespace overview with expandable
+ sections
+ * **New** Breadcrumb navigation at the top of the dashboard
+ * **Improved** Tap and Top pages
+ * Table rendering performance improvements via throttling
+ * Tables now link to resource detail pages
+ * Tap an entire namespace when no resource is specified
+ * Tap websocket errors provide more descriptive text
+ * Consolidated source and destination columns
+ * Misc ui updates
+ * Metrics tables now include a small success rate chart
+ * Improved latency formatting for seconds latencies
+ * Renamed upstream/downstream to inbound/outbound
+ * Sidebar scrolls independently from main panel, scrollbars hidden when not
+ needed
+ * Removed social links from sidebar
+* CLI
+ * **New** `linkerd check` now validates Linkerd proxy versions and readiness
+ * **New** `linkerd inject` now provides an injection status report, and warns
+ when resources are not injectable
+ * **New** `linkerd top` now has a `--hide-sources` flag, to hide the source
+ column and collapse top results accordingly
+* Control Plane
+ * Updated Prometheus to v2.4.0, Grafana to 5.2.4
+
## v18.8.4
* Web UI
