[docs] change server module example to be more realistic

Describe the bug

Problem

export const atlantisCoordinates = [/* redacted */];

https://svelte.dev/docs/kit/server-only-modules#How-it-works

The above can lead users to think that variables / secrets should be stored in a $lib/server/secrets.js when an environment variable is more appropriate.

Proposed Solution

Change the example to show business logic or DB connection

// $lib/server/db.js
  export const db = sql(...)

<script>
// src/routes/+page.svelte
  import { db} from './utils.js';
</script>

Reference

https://discord.com/channels/457912077277855764/1336063679275208814

Reproduction

.

Logs

System Info

.

Severity

annoyance

Additional Information

No response

Start at the server-only-modules documentation section linked in the issue and inspect the current atlantisCoordinates example. Replace it with a realistic business-logic or database-connection example, keeping the accompanying Svelte import example consistent; the documentation is done when it no longer suggests storing secrets in a server module.