Documenting Typing the Extended PrismaClient

I've been running into an issue where the VSCode Typescript errors with errors like the following:
```
Excessive stack depth comparing types...
```
```
This expression is not callable....
```
After searching and consulting with various AI oracles I realized the issue could be solved by removing the prisma-field-encryption extension. This Github issue was a hint, although the discussion is from when clientExtensions were a preview feature.

https://github.com/prisma/prisma/issues/17236

The solution seems to be the following:

```typescript
import { PrismaClient } from '@prisma/client'
import { fieldEncryptionExtension } from 'prisma-field-encryption'
import { type PrismaClientExtends } from '@prisma/client/extension'
import type * as runtime from '@prisma/client/runtime/library'

// Define the extended client type using Prisma's extension type system
type ExtendedClient = PrismaClient & PrismaClientExtends

const globalClient = new PrismaClient()

export const client = globalClient.$extends(
// This is a function, don't forget to call it:
fieldEncryptionExtension()
) as ExtendedClient

export type { ExtendedClient as PrismaClient }
```

Does this fix make sense? It is working nicely for me. If so I'd like to open a PR to add this to the Readme. 🙏

The issue is about adding a TypeScript typing example to the README. Look at the existing README file to see where the usage examples are placed. The provided code snippet shows how to type an extended PrismaClient with the field encryption extension. Verify the snippet works by checking the current extension API in the source code, then update the documentation accordingly.

Scritto dal modello di indicizzazione a partire dal testo della issue.