Let authors write contents of index

As it stands, index is a separate page from [slug] .

As a component designer,

I want to use the same component for rendering any page, not a separate one for index.

Because it's DRY.

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Implementation:

In Astro, slug for index is undefined: https://github.com/withastro/astro/issues/3990

I'll change the directus slug type to allow undefined and then we can set home's slug to undefined.

Edit: See #39 (comment 42327) (tl;dr @jon go ahead and create system collection with index entry.)