Update readme

Author: Warren Buckley

README.md

@@ -187,6 +187,18 @@ It can be used in one of two ways, either by specifying the `src` attribute to a
 <our-svg media-item="@Model.Logo" />
 ```
 
+## `<our-fallback>`
+This tag helper element `<our-fallback>` uses the same fallback mode logic that is only available on the `Value()` method of the `IPublishedContent` interface that uses a string for the property name to lookup. In addition if the fallback value from a language or ancestors is not available we are still able to fallback to the content inside the tag.
+
+```cshtml
+@* Current way *@
+@Model.Value("Header", fallback:Fallback.ToLanguage)
+
+<h3><our-fallback property="Header" mode="Fallback.ToLanguage" culture="da-DK">I do NOT have a DK culture variant of this property</our-fallback></h3>
+<h3><our-fallback property="Header" mode="Fallback.ToAncestors">I do NOT have a Header property set on ANY parent and ancestors</our-fallback></h3> 
+```
+
+
 ## Video 📺
 [![How to create ASP.NET TagHelpers for Umbraco](https://user-images.githubusercontent.com/1389894/138666925-15475216-239f-439d-b989-c67995e5df71.png)](https://www.youtube.com/watch?v=3fkDs0NwIE8)