Update changelog

Author: amotl

CHANGELOG.md

@@ -4,6 +4,7 @@
 - Add test for customization of Leaflet Popup's "autoWidth" option
 - Extract Leaflet's custom "autoWidth" option into "leaflet_plus.ts"
 - Use vanilla Leaflet 1.7.1
+- Add feature to add an image overlay to the map. Thanks, @jreyesr!
 
 ## v0.13.0
 - Update basemaps URL to the new CARTO CDN URL. Thanks, @skgsergio!