v6: tsconfig template update

src/content/docs/en/guides/upgrade-to/v6.mdx

@@ -1284,6 +1284,23 @@ then you will need to update your project code to account for the new `data-*` a
 
 The following changes are considered breaking changes in Astro v6.0. Breaking changes may or may not provide temporary backwards compatibility. If you were using these features, you may have to update your code as recommended in each entry.
 
+### Changed: TypeScript configuration
+
+<SourcePR number="15668" title="feat: update tsconfig template to prepare for TS 6" />
+
+In Astro 5.x, TSConfig templates did not set `compilerOptions.types` and `compilerOptions.libReplacement`.
+
+Astro 6.0 TSConfig templates now set `compilerOptions.types` to `["node"]` and `compilerOptions.libReplacement` to `false` to improve performance and compatibility with the [upcoming TypeScript 6.0](https://devblogs.microsoft.com/typescript/announcing-typescript-6-0-beta) release.
+
+#### What should I do?
+
+If you face any TypeScript errors when upgrading, follow TypeScript's guide:
+
+- [`types` now defaults to `[]`](https://devblogs.microsoft.com/typescript/announcing-typescript-6-0-beta/#types-now-defaults-to-[])
+- [Simple Default Changes](https://devblogs.microsoft.com/typescript/announcing-typescript-6-0-beta/#simple-default-changes)
+
+<ReadMore>Read more about [TypeScript configuration in Astro](/en/guides/typescript/#setup).</ReadMore>
+
 ### Changed: endpoints with a file extension cannot be accessed with a trailing slash
 
 <SourcePR number="14457" title="feat!: trailing slash never for endpoints with file extension"/>