docs(v4): add "Hyperlink Image" section in migration guide (#606)

v4/v4-migration-guide.md

@@ -17,15 +17,15 @@ theme = "bilberry-hugo-theme/v4"
 
 ### Top Navigation Bar
 
-1. Remove completely the `excludeFromTopNav` variable from all content files in the `content/page` folder.
-2. Update front matter variables in the pages that used to display menu items in the top navigation bar as follows:
-    * Add the `menu` front matter variable with setting it to the `"topnav"` value: `menu: "topnav"`.
-    * If you want to order displayed menu items, add the `weight` variable with setting it to a non-zero value, for
+1. Remove the `excludeFromTopNav` variable from all content files in the `content/page` folder altogether.
+2. Update front matter variables in the pages that are used to display menu items in the top navigation bar as follows:
+    * Add the `menu` front matter variable by setting it to the `"topnav"` value: `menu: "topnav"`.
+    * If you want to order displayed menu items, add the `weight` variable by setting it to a non-zero value, for
       instance, `weight: 10`. A menu item with a lower `weight` will be displayed first. 
 
 ### Syntax Highlighting
 
-No modifications are needed for posts with any existing code blocks. Syntax highlighting will work the same way as with
+No modifications are needed for posts with any existing code blocks. Syntax highlighting will work the same as with
 the `v3` version. Please see the [Syntax Highlighting](README.md#syntax-highlighting) section in the `v4` **README** 
 guide for customization options.
 
@@ -43,5 +43,11 @@ The Magnific Popup plugin that provided a lightbox for displaying larger images
 the [DimBox](https://dimboxjs.com/) plugin. Also, the built-in Hugo's rendering of images added using standard markdown
 annotation was overridden to accommodate the DimBox plugin and images with a figure caption. The `v4` no longer
 supports the modal zoom for the images added using the raw HTML. The modal zoom may work for such images if you enrich
-corresponding raw HTML elements with DimBox's attributes.     
-
+corresponding raw HTML elements with DimBox's attributes.   
+
+### Hyperlink Image
+Hyperlink images are no longer supported using the standard markdown. Instead, you should use the `hyperlink-image` shortcode for 
+that. See the ["Hyperlink Image"](https://github.com/Lednerb/bilberry-hugo-theme#hyperlink-image) section in the `v4` 
+**README** for more details. Here is an [example](https://github.com/igor-baiborodine/bilberry-hugo-theme-sandbox/commit/b6881726c2d5580f1ca4c32a646ac3bb252e62f0) of such migration from the standard markdown to the 
+`hyperlink-image` migration.
+