Add annotations for custom code to export, shown in published Specs view
It would be nice to have an area that you could have exportable code like html and css. Also allowing you to add in any related custom code for a particular element that you click on in the dev spec.
At first glance this sounds very similar to https://adobexd.uservoice.com/forums/353007/suggestions/13057005-export-artboards-or-entire-project-as-html ...but I think what you're asking for here is more about *manually* attaching your own HTML/CSS code to parts of the XD design -- not asking for XD to automatically generate HTML/CSS for you like that other suggestion is requesting, right?
I'll adjust the title here to make that distinction more clear.
You may also want to upvote https://adobexd.uservoice.com/forums/353007/suggestions/32679022-annotate-parts-of-the-design-publish-annotations, which is a very similar (but more generic) feature request.
Thomas Drenning commented
This would be a huge addon for as well. When making a component library it would be great to be able to embed selectable code snippets that can be used by developers such as what is done and show in popular responsive design framework documentation such as bootstrap.