Update CHANGELOG.md

Author: Collin Delphia

CHANGELOG.md

@@ -6,6 +6,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+## [2021-09-13T18.53.45] - 2021-09-13
+
+### Updated
+
+-   Updated `insertGalleryContent` documentation with inclusion of `insertMethod`
 
 ## [v2021-08-24T18.08.15] - 2021-08-24