Function addToCart

addToCart(
    type: SearchTrackOptions,
    hit: SearchHitWithSku,
    quantity?: number,
): Promise<void>
Adds a search hit to the cart.
Parameters
- type: SearchTrackOptions
  The type of search that the hit belongs to.
- hit: SearchHitWithSku
  The search hit to add to the cart.
- quantity: number = 1
  The quantity of the hit to add to the cart.
Returns Promise<void>
Example
```
import { addToCart } from '@nosto/search-js'

// Add a single product to cart
await addToCart('serp', {
  productId: '123',
  skuId: 'sku-123'
})

// Add multiple quantities
await addToCart('serp', {
  productId: '456',
  skuId: 'sku-456'
}, 3)
```
- Defined in packages/core/src/addToCart.ts:30