TS error: params incorrectly

The [**Generate Dynamic Embed Images**](https://github.com/base/docs/blob/master/docs/mini-apps/technical-guides/dynamic-embeds.mdx) guide in the Base documentation contains an incorrect TypeScript typing for `params` in Next.js App Router examples.

Currently, the documentation types `params` as a `Promise<{ username: string }>` and accesses it using:

```tsx
const { username } = await params;
```

However, in Next.js App Router:
- params is always a synchronous object
- is not a Promise
- its type is { username: string }

Using the code in the current example results in an error:
`TS2741: Property ‘username’ is missing in type ‘Promise<{ username: string; }>’ but required in type '{ username: string; }'`

**After the correction, the code compiles without errors.**

This issue has been addressed in [**PR#1108**](https://github.com/base/docs/pull/1108)
The PR updates all affected examples to the correct typing and removes `await` params.