Wrap heading section numbers in <span class=secno>

[sideshowbarker]

Addresses #27.

[domenic]

Ah, sorry for not updating #27, but in #30 (comment) @annevk mentioned he'd prefer we only output this in the dev edition. I'm not sure that's a great idea personally---I can imagine our future selves getting very confused about the divergence in markup between the two while tweaking some stylesheets---but that's where we landed last time. @annevk, thoughts?

[annevk]

I'm somewhat indifferent at this point. My main quibble is that the generated HTML of Bikeshed is way out of proportion to what it could be I think so I'd rather not do anything just to match that, but if this helps make progress just go ahead. It's a larger issue anyway.

[sideshowbarker]

in #30 (comment) @annevk mentioned he'd prefer we only output this in the dev edition. I'm not sure that's a great idea personally---I can imagine our future selves getting very confused about the divergence in markup between the two while tweaking some stylesheets

If we do decide we only need it for the dev edition, I’m pretty sure it’s possible (maybe even easy) to make wattsi only do it for the dev edition

[domenic]

Let's merge this as-is then; although I understand @annevk's concerns in general, and applied them in #30 by removing my addition of Bikeshed's heading class, I feel more comfortable having the same markup structure between the two editions.