Prepare changelog for v1.7.26

Author: RiotRobot

CHANGELOG.md

@@ -1,3 +1,9 @@
+Changes in [1.7.26](https://github.com/vector-im/element-web/releases/tag/v1.7.26) (2021-04-26)
+===============================================================================================
+[Full Changelog](https://github.com/vector-im/element-web/compare/v1.7.26-rc.1...v1.7.26)
+
+ * Upgrade to React SDK 3.19.0 and JS SDK 10.0.0
+
 Changes in [1.7.26-rc.1](https://github.com/vector-im/element-web/releases/tag/v1.7.26-rc.1) (2021-04-21)
 =========================================================================================================
 [Full Changelog](https://github.com/vector-im/element-web/compare/v1.7.25...v1.7.26-rc.1)