(DOCSP-18273) v1.26.1 release notes (#495)

* (DOCSP-18273) v1.26.1 release notes

Author: zach-carr

source/release-notes.txt

@@ -10,6 +10,28 @@ MongoDB Charts Cloud Release Notes
    :depth: 1
    :class: twocols
 
+|charts| v1.26.1
+----------------
+
+*Released August 19, 2021*
+
+Bug fixes in this release:
+
+- Fixes an issue with disabling interactive filters on some 
+  dashboards created before v1.26.0.
+
+- Grouped column charts with secondary axes now render properly.
+
+- Donut charts with :guilabel:`By Series` colors now display properly 
+  when data changes.
+
+- Pressing the ‘Enter’ key to create a new dashboard now works 
+  correctly.
+
+- Fixes an issue where data driven multi-series charts could not be 
+  embedded.
+
+
 |charts| v1.26.0
 ----------------