Add changelog entries.

CHANGES.md

@@ -12,10 +12,13 @@ Fixed issues:
 * [#4875](https://github.com/ckeditor/ckeditor4/issues/4875): Fixed: Not possible to delete multiple selected lists.
 * [#4873](https://github.com/ckeditor/ckeditor4/issues/4873): Fixed: Pasting content from MS Word and Outlook with horizontal lines prevents images from being uploaded.
 * [#4952](https://github.com/ckeditor/ckeditor4/issues/4952): Fixed: Dragging and dropping images within a table cells appends additional elements.
+* [#4761](https://github.com/ckeditor/ckeditor4/issues/4761): Fixed: not all resources loaded by the editor respect the cache key.
 
 API changes:
 
 * [#4918](https://github.com/ckeditor/ckeditor4/issues/4918): Explicitly set [`config.useComputedState`](https://ckeditor.com/docs/ckeditor4/latest/api/CKEDITOR_config.html#cfg-useComputedState) default value to `true`. Thanks to [Shabab Karim](https://github.com/shabab477)!
+* [#4761](https://github.com/ckeditor/ckeditor4/issues/4761): [`CKEDITOR.appendTimestamp()`](https://ckeditor.com/docs/ckeditor4/latest/api/CKEDITOR.html#method-appendTimestamp) function was added.
+* [#4761](https://github.com/ckeditor/ckeditor4/issues/4761): [`CKEDITOR.dom.document#appendStyleSheet()`](https://ckeditor.com/docs/ckeditor4/latest/api/CKEDITOR_dom_document.html#method-appendStyleSheet) and [`CKEDITOR.tools.buildStyleHtml()`](https://ckeditor.com/docs/ckeditor4/latest/api/CKEDITOR_tools.html#method-buildStyleHtml) now use newly added [`CKEDITOR.appendTimestamp()`](https://ckeditor.com/docs/ckeditor4/latest/api/CKEDITOR.html#method-appendTimestamp) function to correctly handle caching of CSS files.
 
 Other changes: