[fix] add app.d.ts to template

[baseballyama]

fix: #4241

After committing #4118 , type checker can not find ambient module.
It seems that tsconfig.json can only read ambient module that is a subdirectory of it.
(Now tsconfig.json is at inside of .svelte-kit folder but ambient module is inside of ./node_modules/@sveltejs/kit/types.)
So AFAIK, we need to tell ambient module somehow.
So I added app.d.ts at root.
If you have a better way, please correct me!

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🦋 Changeset detected

Latest commit: d925490

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
default-template	Patch
create-svelte	Patch

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[dummdidumm]

Can't validate this myself today but I would be surprised if "extends" prevents app.d.ts from including the modules. AFAIK tsconfig is merged first and then loaded as if everything is in the tsconfig that extends the other.

[baseballyama]

To be honest I am confused by this. Since .svelte-kit/tsconfig.ts is used via jsconfig.json, I was expecting node_modules to be treated as a subdirectory.
But in fact, it seems not.

if "extends" prevents app.d.ts from including the modules.

Maybe I didn't get the meaning of this.
Without the PR, the template doesn't provide app.d.ts. And after adding app.d.ts, type checker recognizes app.d.ts and type checker recognizes the ambient module through it.

[baseballyama]

@Conduitry

Now I'm facing a deploy error that I faced yesterday in my local.
#4239 (comment)
https://app.netlify.com/sites/kit-demo/deploys/622468f183e8a9000860529a#L1048

Maybe yesterday's deploy process used cache or something? (I didn't get why it was succeeded...)
But anyway I think again we need to add @sveltejs/adapter-static ...

[baseballyama]

This is because while parsing this code, an error occurred inside shiki-twoslash because cannot find module @sveltejs/adapter-static.
https://github.com/sveltejs/kit/blob/master/documentation/docs/13-configuration.md?plain=1#L243

[2307] 20 - Cannot find module '@sveltejs[/adapter-static]()' or its corresponding type declarations.
Please report this to [https://github.com/markedjs/marked]().
    at [/Users/baseballyama/Desktop/git/svelte-contributes/kit/node_modules/.pnpm/]()@typescript+twoslash@3.1.0[/node_modules/]()@typescript[/twoslash/dist/twoslash.cjs.production.min.js:1:12381]()
    at Object.exports.twoslasher ([/Users/baseballyama/Desktop/git/svelte-contributes/kit/node_modules/.pnpm/]()@typescript+twoslash@3.1.0[/node_modules/]()@typescript[/twoslash/dist/twoslash.cjs.production.min.js:1:12593]())
    at exports.runTwoSlash ([/Users/baseballyama/Desktop/git/svelte-contributes/kit/node_modules/.pnpm/shiki-twoslash]()@3.0.2[/node_modules/shiki-twoslash/dist/shiki-twoslash.cjs.production.min.js:1:22890]())
    at code ([file:///Users/baseballyama/Desktop/git/svelte-contributes/kit/sites/kit.svelte.dev/.svelte-kit/output/server/chunks/index-6307d1fd.js:651:26]())
    at Renderer.code ([file:///Users/baseballyama/Desktop/git/svelte-contributes/kit/sites/kit.svelte.dev/.svelte-kit/output/server/chunks/index-6307d1fd.js:788:33]())
    at Renderer.renderer.<computed> [as code] ([file:///Users/baseballyama/Desktop/git/svelte-contributes/kit/node_modules/.pnpm/marked@4.0.5/node_modules/marked/lib/marked.esm.js:2544:41]())
    at Parser.parse ([file:///Users/baseballyama/Desktop/git/svelte-contributes/kit/node_modules/.pnpm/marked@4.0.5/node_modules/marked/lib/marked.esm.js:2157:32]())
    at Parser.parse ([file:///Users/baseballyama/Desktop/git/svelte-contributes/kit/node_modules/.pnpm/marked@4.0.5/node_modules/marked/lib/marked.esm.js:2232:30]())
    at Parser.parse ([file:///Users/baseballyama/Desktop/git/svelte-contributes/kit/node_modules/.pnpm/marked@4.0.5/node_modules/marked/lib/marked.esm.js:2232:30]())
    at Function.parse ([file:///Users/baseballyama/Desktop/git/svelte-contributes/kit/node_modules/.pnpm/marked@4.0.5/node_modules/marked/lib/marked.esm.js:2091:19]())

This PR added js check, therefore I think shiki-twoslash tried to check it but originally module does not exist.
#4011

https://github.com/sveltejs/kit/pull/4011/files#diff-28812e50c84eb6916715a197501054d6481bb671e82a8cf57f75514ff381c22cR80

We may end up registering all adapters in package.jsonof site, but it is important that the documentation be accurate, so we are willing to allow for that.

[baseballyama]

The deployment was successful by incorporating another PR. (#4245)
Therefore, I changed the status to ready for review.

[Rich-Harris]

I'm not sure I understand this? There's already src/app.d.ts and I just confirmed (in a new project) that it works fine:

[Rich-Harris]

I believe #4295 was the underlying issue, so I'll close this — thanks