Render Svelte document languages in snapshots

Amp-Thread-ID: https://ampcode.com/threads/T-01a029e2-5095-710a-9cce-0c6d8645c173

Author: eseliger

snapshots/output/multi-project/packages/a/src/Component.svelte

@@ -1,3 +1,4 @@
+// language Svelte
 // < definition @example/a 1.0.0 src/`Component.svelte`/
 
 <script lang="ts">

snapshots/output/multi-project/packages/b/src/App.svelte

@@ -1,3 +1,4 @@
+// language Svelte
 // < definition @example/b 1.0.0 src/`App.svelte`/
 
 <script lang="ts">

snapshots/output/svelte/Child.svelte

@@ -1,3 +1,4 @@
+// language Svelte
 // < definition svelte-example 1.0.0 `Child.svelte`/
 
 <script lang="ts">

snapshots/output/svelte/Generic.svelte

@@ -1,3 +1,4 @@
+// language Svelte
 // < definition svelte-example 1.0.0 `Generic.svelte`/
 
 <script lang="ts" generics="Value">

snapshots/output/svelte/Legacy.svelte

@@ -1,3 +1,4 @@
+// language Svelte
 // < definition svelte-example 1.0.0 `Legacy.svelte`/
 
 <script lang="ts">

snapshots/output/svelte/Parent.svelte

@@ -1,3 +1,4 @@
+// language Svelte
 // < definition svelte-example 1.0.0 `Parent.svelte`/
 
 <script lang="ts">

snapshots/output/svelte/Plain.svelte

@@ -1,3 +1,4 @@
+// language Svelte
 // < definition svelte-example 1.0.0 `Plain.svelte`/
 
 <script>

snapshots/output/svelte/helper.ts

@@ -1,3 +1,4 @@
+// language TypeScript
 // < definition svelte-example 1.0.0 `helper.ts`/
 
 export interface User {

snapshots/output/svelte/index.ts

@@ -1,3 +1,4 @@
+// language TypeScript
 // < definition svelte-example 1.0.0 `index.ts`/
 
 import Legacy from './Legacy.svelte'

snapshots/output/svelte/stores.ts

@@ -1,3 +1,4 @@
+// language TypeScript
 // < definition svelte-example 1.0.0 `stores.ts`/
 
 import { writable } from 'svelte/store'