Add abbreviation for slot

[anthonyvdotbe]

slot should be expanded to <slot name=""></slot>, with the caret first inside the name attribute and then inside the element itself.

[sergeche]

slot[name].

[anthonyvdotbe]

AFAIK a slot without a name doesn't have a use case, so that's why I'd like to have just slot be sufficient, equivalent to how just a also adds the href attribute and expands to <a href=""></a>

[sergeche]

<slot> element without name is a default slot that receives any custom element content without slot attribute