Add a comment on something that needs fixing in the reader

Author: AngledLuffa

src/edu/stanford/nlp/pipeline/CoNLLUReader.java

@@ -164,6 +164,7 @@ else if (MWT_LINE.matcher(line).matches())
       else if (TOKEN_LINE.matcher(line).matches())
         tokenLines.add(line);
       else
+        // TODO: this is ignoring "empty" tokens
         return true;
       return false;
     }