Include adders from `svelte-add` (v2)

[manuel3108]

A few days ago, @benmccann came up with the idea of integrating svelte-add into the new v2 site. The goal would be to make people aware of that this project exists and potentially directly link them from the official svelte / kit sites.

Based on my recent commitment to a full rewrite of svelte-add, I personally really like that idea. The rewrite is currently usable, although published as svelte-compose as im still in the process of getting access to the svelte-add npm org.

I could imagine having something like on the website I have currently published https://svelte-compose.com/.

We would need to decide if the configurator displayed below would make sense in this context, but I think especially for newcomers this takes away a lot of uncertainty.

What do you think? Would this be an interesting addition? Would this addition work well with the packages & templates shown on the current website?

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Technical details:
Currently one of the packages (@svelte-compose/cli) is exposing an internal API to get a list of adders and their respective metadata. Based on that information the page is fully prerendered during build and then published to github pages. If the separate website would need to co-exists remains unclear at this point.