Shorthand for Named Slots

Named slots also have a shorthand syntax, one that's much nicer to look at.

Instead of writing this:

<DataTable>
<template v-slot:header>
<TableHeader />
</template>
</DataTable>

We can write this:

<DataTable>
<template #header>
<TableHeader />
</template>
</DataTable>

Not a huge difference, but a little cleaner for sure. I think the # character is easier to pick out than v-slot when reading code.