Auto tags based on names

[kizu]

We could set tag names (if they're not defined) based on the block/element names.

For example, if we do +b.menu we treat it as +b('ul').menu by default.

If we have +b.header — make it +b('header').header.

The thing to think on — if there are names in modifiers, for example — what would have more priority? The modifier seems more appropriate for me — so +b.section_footer would give us +b('footer').section_footer