Dedent markup in icon shortcode

layouts/shortcodes/paige/icon.html

@@ -8,6 +8,8 @@
     {{ errorf "layouts/shortcodes/paige/icon.html: no class" }}
 {{ end }}
 
+{{/* The markup below cannot be indented due to nested shortcodes within Markdown. */}}
+
 <span class="paige-icon">
 {{ with $url }}
 <a href="{{ . }}" {{ with $target }} target="{{ . }}" {{ end }} {{ with $title }} title="{{ . }}" {{ end }}>