feat: document locals in adapter API

[ematipico]

What kind of changes does this PR include?

• New or updated content

Description

Relevant PR: withastro/astro#7385

This PR adds a new paragraph to the app.render heading. Unfortunately, I don't know enough to explain the second argument (routeData), so I left a TODO there.

It would be great if we could document it in this PR, but I would need some help.

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[sarah11918]

Thanks for this, @ematipico! I took a shot at using links to content we already have to see if this could work for the section. What do you think? Do you think this is complete enough?

[ematipico]

@sarah11918 thank you for the review, everything looks good to me!

[yanthomasdev]

Small nit, overall LGTM!

[ematipico]

@matthewp could you please advice on how we can explain routeData (second argument) of the render function?

[matthewp]

That's a lot of stuff to document. Do we have any way to point that arg to a type that's defined?

[ematipico]

That's a lot of stuff to document. Do we have any way to point that arg to a type that's defined?

I was thinking to document only when/why an adapter can pass a RouteData, and a brief example.

[ematipico]

@sarah11918 @Yan-Thomas added a small paragraph about the second optional parameter.

[sarah11918]

Thanks, @ematipico ! Nice to have an example here!