Added extensible converter

src/ExtensibleCommonMarkConverter.php

@@ -0,0 +1,33 @@
+<?php
+
+/*
+ * This file is part of the league/commonmark package.
+ *
+ * (c) Colin O'Dell <colinodell@gmail.com>
+ *
+ * Original code based on the CommonMark JS reference parser (http://bitly.com/commonmark-js)
+ *  - (c) John MacFarlane
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace League\CommonMark;
+
+/**
+ * Converts CommonMark-compatible Markdown to HTML.
+ */
+class ExtensibleCommonMarkConverter extends CommonMarkConverter
+{
+    /**
+     * Create a new commonmark converter instance.
+     *
+     * @param DocParser $docParser
+     * @param HtmlRendererInterface $htmlRenderer
+     */
+    public function __construct(DocParser $docParser, HtmlRendererInterface $htmlRenderer)
+    {
+        $this->docParser = $docParser;
+        $this->htmlRenderer = $htmlRenderer;
+    }
+}