[examples] Add Vercel Analytics for CRA/SvelteKit templates. (#7894)

Successfully tested with:

- [CRA](https://front-git-analytics-for-all-frameworks.vercel.sh/now-examples/create-react-app/analytics?device=desktop&timePeriod=1d&percentile=75&timeInterval=3h&sort=datapoints&search=)
- [SvelteKit](https://front-git-analytics-for-all-frameworks.vercel.sh/now-examples/sveltekit/analytics?device=desktop&timePeriod=1d&percentile=75&timeInterval=3h&sort=datapoints&search=)

Dependencies have also been updated 👍

examples/sveltekit/svelte.config.js

@@ -1,7 +1,13 @@
 import adapter from '@sveltejs/adapter-auto';
+import preprocess from 'svelte-preprocess';
 
 /** @type {import('@sveltejs/kit').Config} */
 const config = {
+  preprocess: preprocess({
+    replace: [
+      ['import.meta.env.VERCEL_ANALYTICS_ID', JSON.stringify(process.env.VERCEL_ANALYTICS_ID)]
+    ]
+  }),
   kit: {
     adapter: adapter(),