docs(concepts) make islands.md examples run without errors

[rawlingsr]

Addresses #1582

I've tried to break up my changes so that only the first one or two commits can be taken if they are the only ones that are helpful.

[marvinhagemeister]

Thanks for making a PR! This is great!!

Left two minor nit comments because the first argument to components is usually called Props not Data. It's more of a convention not a hard rule, but that makes it easier for folks coming from other frameworks.

The correct type for children is ComponentChildren in Preact instead of VNode<Element>

[rawlingsr]

@marvinhagemeister Thank you for the changes, and for the feedback.

I wanted to make one other change, but I am not sure what the text should say instead of what it says now. There is a paragraph that talks about not needing to serialize children: https://github.com/setibeings/fresh/blob/eafe8a901a3c9496561cc6b0059882a44e649747/docs/latest/concepts/islands.md?plain=1#L105C1-L109C1

It uses the pronoun "we" which I think could trip somebody up if they aren't sure if they're reading about something that THEY should be able to tell by looking at the HTML returned by the server.

[marvinhagemeister]

@setibeings Good catch. Looks like that is a copy & paste error from the blog post on my part. That section is meant to refer to Fresh the framework itself.

[rawlingsr]

I'm not sure if this is the blog post, but I'll just plan on reading it today and take a crack at rephrasing the paragraph I mentioned.

https://deno.com/blog/intro-to-islands

[marvinhagemeister]

@setibeings it references a section from this blog post https://deno.com/blog/fresh-1.2#passing-jsx-to-islands-and-nesting-islands-within-each-other

[marvinhagemeister]

Looks like there is a formatting error. Running deno fmt locally will resolve these and make the CI green 👍

[rawlingsr]

Converting to draft because I now want to add an HTML Example.

[rawlingsr]

Take a look at what I wrote and let me know if it matches what you think when you get a moment. Thanks for bearing with me.

[marvinhagemeister]

LGTM, thanks for making the PR 💯