feat: add PageProps to $./types

.changeset/spotty-jars-kiss.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': major
+---
+
+Add 'PageProps' to './$types'

documentation/docs/02-runes/05-$props.md

@@ -0,0 +1,28 @@
+<!-- Append to the end of page -->
+### PageProps
+
+For defining types of `$props` rune in `page.svelte`, you would normally do the following
+
+```svelte
+<!--- file: page.svelte --->
+<script>
+  import { PageData } from './$types';
+
+  interface Props {
+    data: PageData;
+  }
+
+	let { data }: Props = $props();
+</script>
+```
+
+If you don't want to write this for every page, you can do the following instead
+
+```svelte
+<!--- file: page.svelte --->
+<script>
+	import { PageProps } from './$types';
+
+	let { data }: PageProps = $props();
+</script>
+```

packages/kit/src/core/sync/write_types/index.js

@@ -465,6 +465,12 @@ function process_node(node, outdir, is_page, proxies, all_pages_have_load = true
 
 	exports.push(`export type ${prefix}Data = ${data};`);
 
+	exports.push(
+		`export type ${prefix}Props = { data: ${prefix}Data; ${
+			node.server && is_page ? 'form: ActionData; ' : ''
+		}};`
+	);
+
 	return { declarations, exports, proxies };
 
 	/**