Add Visitor for Code Spans

Author: rdestefa

commonmark/src/main/java/org/commonmark/renderer/html/CoreHtmlNodeRenderer.java

@@ -311,6 +311,11 @@ public void visit(Text text) {
             sb.append(text.getLiteral());
         }
 
+        @Override
+        public void visit(Code code) {
+            sb.append(code.getLiteral());
+        }
+
         @Override
         public void visit(SoftLineBreak softLineBreak) {
             sb.append('\n');