emit short tag on empty blocks

[HookedBehemoth]

This changes the emited markup with tags like this: use href="#page" {} from <use href="#page"></use> to <use href="#page"/>. Other tags this is useful for are e.g. video and all svg subtags.

[zr40]

Unfortunately <foo/> is not correct according to the spec:

Start tags consist of the following parts, in exactly the following order:

1. A "<" character.
2. The element’s tag name.
3. Optionally, one or more attributes, each of which must be preceded by one or more space characters.
4. Optionally, one or more space characters.
5. Optionally, a "/" character, which may be present only if the element is a void element.
6. A ">" character.

The optional / character has no significance to HTML parsers, so it does not have the effect you desire. For instance, <div/><div/> is equivalent to <div><div>.

For void elements, those that do not require a closing tag, you can use ; instead of {}.

[HookedBehemoth]

Thanks for letting me know. Came from xmpp and just assumed this would be XML standard.

[lambda-fairy]

I have a pending feature request for XML support at #62. It's a bit more complicated than it looks because of 🅰️ context-aware escaping and 🅱️ namespaces.