'usage-notes' is not present in html/elements/abbr

[peterbe]

Pretty sure the reason is because of

<!-- <usage-notes> -->

in https://raw.githubusercontent.com/mdn/stumptown-experiment/master/content/html/elements/abbr/prose.md

I found this out the hard way when trying to render this with mdn2.

I really hope we can soon build a linter here in this project and run it in CI.

[peterbe]

Hmm... I fixed the <!-- <usage-notes> --> but the abbr/prose.md exhibits the same problems with <!-- see-also --> that I think we had with elements/video/prose.md and the <!-- see-also -->

[wbamberg]

I think until we have a reasonably stable resolution for https://github.com/mdn/stumptown-experiment/issues/19, there's not much point fixing this in lots of prose.md files.