Add preserveDirectoryStructure adapter feature

[matthewp]

Description (required)

Adds new preserveDirectoryStructure option to the adapter features that preserves config.build.client on static builds.

Related issues & labels (optional)

For Astro version: 6.x. See astro PR #15694.

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Warnings reference

Icon	Description
🔄️	The source for this localization has been updated since the creation of this pull request, make sure all changes in the source have been applied.

[sarah11918]

Suggested change

	<Since v="6.0.0" />
	**Default:** `false`<br />
	<Since v="6.0.0" />

Sounds like this is false by default. ( @ArmandPhilippot I'm noticing staticHeaders above doesn't specify a default either, and probably should? Just want to check with you since you recently worked on this page though!)

[ArmandPhilippot]

Yeah, in both cases undefined or false behave the same. So, I think we can add a default here. IIRC, we've already done that in a few places!

[sarah11918]

Perfect, thanks! I think that should be all that's needed here then, to add default: false in both places!

[matthewp]

Ok, will update tomorrow.