[Docs] Add example for combining multiple middleware in Prisma Client

[therbta]

Problem

The current documentation shows individual middleware examples, but doesn't demonstrate how to properly chain multiple middleware together with proper TypeScript typing.

Suggested Addition

Add a section under the Middleware docs showing:

1. How to compose multiple middleware
2. How to handle typing when middleware modifies the query/result
3. Best practices for middleware ordering

Example Code Needed

const prisma = new PrismaClient().$extends({
  query: {
    $allModels: {
      async $allOperations({ model, operation, args, query }) {
        // Logging middleware
        const start = Date.now()
        const result = await query(args)
        console.log(`${model}.${operation} took ${Date.now() - start}ms`)
        return result
      }
    }
  }
})

Why This Matters

Many production apps need multiple middleware (logging, soft deletes, multi-tenancy). Clear examples would help adoption.