Fetches a Kirby URL parameter
Additional to URL query variables you can set parameters via URL in Kirby in a more human readable way:
http://yourdomain.com/blog/tag:mytag/year:2014
Those parameters are very handy when you want to build URL-based filters for your content.
Such parameters will be ignored by the router so the URL which will be fetched by Kirby in this case is http://yourdomain.com/blog
The parameters can be fetched in templates, snippets or controllers like this:
$tag = param('tag');
$year = param('year');
You can even define a default value when a parameter is not set:
$tag = param('tag', 'design');
$year = param('year', 2014);