parse code span after recursive types to resolve #44

tests/data/inline_link.html

@@ -1,2 +1,3 @@
 <p><a href="http://example.com">link</a></p>
+<p><a href="http://example.com"><code>link</code></a></p>
 <p><a href="http://example.com"><img alt="MD Logo" src="http://parsedown.org/md.png"></a></p>

tests/data/inline_link.md

@@ -1,3 +1,5 @@
 [link](http://example.com)
 
+[`link`](http://example.com)
+
 [![MD Logo](http://parsedown.org/md.png)](http://example.com)

tests/data/text_reference.html

@@ -3,4 +3,5 @@
 <p>[one][404] with no definition</p>
 <p><a href="http://example.com">multiline
 one</a> defined on 2 lines</p>
-<p><a href="http://example.com">one</a> with an upper case label</p>
+<p><a href="http://example.com">one</a> with an upper case label</p>
+<p><a href="http://example.com"><code>link</code></a></p>

tests/data/text_reference.md

@@ -13,4 +13,6 @@ one][website] defined on 2 lines
 
 [one][label] with an upper case label
 
-[LABEL]: http://example.com
+[LABEL]: http://example.com
+
+[`link`][website]