Add a benefit and a simple example to return current year

Thanks @bep!

docs/content/extras/shortcodes.md

@@ -1,7 +1,7 @@
 ---
 aliases:
 - /doc/shortcodes/
-lastmod: 2015-11-29
+lastmod: 2016-02-03
 date: 2013-07-01
 menu:
   main:
@@ -29,6 +29,10 @@ using a predefined template. Note that shortcodes will not work in template
 files---if you need a functionality like that in a template, you most likely
 want a [partial template](/templates/partials/) instead.
 
+Another benefit is, you can update your shortcode with any related new classes or
+techniques, and upon generation, Hugo will easily merge in your changes. You
+avoid a possibly complicated search and replace operation.
+
 ## Using a shortcode
 
 In your content files, a shortcode can be called by using the `{{%/* name parameters
@@ -373,4 +377,14 @@ And will be rendered as:
 Please notice that this template makes use of a Hugo-specific template function
 called `highlight` which uses Pygments to add the highlighting code.
 
+## Simple Single-word Example: Year
+
+Let's assume you would like to have a shortcode to be replaced by the current year in your Markdown content files, for a license or copyright statement. Calling a shortcode like this:
+
+    {{</* year */>}}
+
+... would load your one-line template ``/layouts/shortcodes/year.html``, which contains:
+
+    {{ .Page.Now.Year }}
+
 More shortcode examples can be found at [spf13.com](https://github.com/spf13/spf13.com/tree/master/layouts/shortcodes).