Thanks for the input. I created an issue for it https://github.com/mocco/feedhuddler/issues/52. I haven't looked into wallabag, so I don't now if we are able to do it. The issue will be updated with status as I look into it.
"Learning Haskell" is filled in the description of the gist. Descriptions can be fairly lengthy and not always suitable as titles. However, I think it would be awesome to support metadata in a form like in Jekyll posts or something similar.