add trendz 1.8 release notes

Author: vparomskiy

docs/trendz/releases.md

@@ -8,6 +8,37 @@ description: ThingsBoard Trendz Analytics Release Notes
 * TOC
 {:toc}
 
+## v1.8.0 (August, 2021)
+
+**Improvements:**
+
+ * Add persistent cache for states, simple and calculated fields
+ * Add view report short term cache
+ * Scheduled field cache refresh
+ * Add native widget bundle for ThingsBoard
+ * Change rendering engine for views that uses canvas
+ * Add simplified REST API for 3rd party services
+ * Add date click event for calendar view
+ * Add row click event for tables
+ * Add field changed event for switch config
+ * Save state & calculated fields configuration
+ * Improve query partitioning
+ * Improve anomalies loading time
+ * Add option for loading raw telemetry instead of partitioning
+ * Add preview/edit links for views added on the dashboard
+ * Add option for mark field as hidden in view
+ 
+
+**Bug fixes:**
+
+ * Table - fix total row when first field is not static
+ * Clear duplicates when anomaly detection model cloned
+ * Fix state duration percent calculation
+ * Fix interval formatting issue on horizontal charts
+ * Fix not valid JWT token storage
+ * Fix deadlock in batch field calculation
+
+
 ## v1.7.0 (April, 2021)
 
 **Improvements:**