Document branch diff list in publish panel

editor/git-essentials.mdx

@@ -52,7 +52,7 @@ These are the Git concepts you'll encounter most often when using the web editor
     Occurs when two people change the same part of a file differently. The editor helps resolve any conflicts that occur on your branches.
   </Accordion>
   <Accordion title="Diff">
-    A comparison showing the differences between two versions of a file. When reviewing pull requests, diffs highlight exactly what changed.
+    A comparison showing the differences between two versions of a file. When reviewing pull requests, diffs highlight exactly what changed. The web editor can show diffs for individual files when you review branch changes before publishing.
   </Accordion>
 </AccordionGroup>
 

editor/publish.mdx

@@ -54,6 +54,14 @@ When you work on a feature branch, save changes to the branch.
 
 To discard changes, click **Undo changes** beside a filename in the files changed dropdown.
 
+## Review branch changes
+
+When you work on a feature branch, the publish panel shows all file changes between your branch and the deployment branch under **Saved in branch**. This includes changes saved by you and any teammates working on the same branch.
+
+Click a file in the list to open a diff view showing changes between the branch and published content. Documentation files open in a visual diff, and other file types open in a source diff. Use this to review the full scope of changes on a branch before publishing.
+
+Files that can't display a diff, such as images or removed files, appear in the list but aren't clickable.
+
 ## Publish your changes
 
 Click **Publish** in the toolbar. Depending on your workflow, your changes deploy immediately or create a pull request for you to merge in your Git provider. If you are on a feature branch, save your changes before publishing.