added usage example

README.md

@@ -112,6 +112,25 @@ or via reference to [a later defined url][massivedynamic], i we so desire.
 
 [massivedynamic]: https://massivedynamic.eu
 
+## Usage
+Simply construct an new `parkdown\Parkdown` object and pass the Markdown source code to it's constructor. The parsed `DOMDocument` or it's `HTML` output can then be retrieved through the `::html()` and `::tree()` member functions.
+
+**Example**
+
+```php
+	use parkdown\Parkdown;
+
+	$source = "
+		This is a **bold** word in a paragraph.
+	";
+
+	$parser = new Parkdown($source);
+	$tree   = $parser->tree();
+
+	print_r($tree);
+	echo $parser->html();
+```
+
 ## Testing
 Unit tests can be run via `composer`: