docs: clarify pageNumber

Author: rocwang

README.md

@@ -29,13 +29,13 @@ npm install vue-virtual-scroll-grid
 
 ## Available Props
 
-| Name                       | Description                                                               | Type                                                           | Validation                                           |
-| -------------------------- | ------------------------------------------------------------------------- | -------------------------------------------------------------- | ---------------------------------------------------- |
-| `length`                   | The number of items in the list                                           | `number`                                                       | Required, an integer greater than or equal to 0      |
-| `pageProvider`             | The callback that returns a page of items as a promise                    | `(pageNumber: number, pageSize: number) => Promise<unknown[]>` | Required                                             |
-| `pageProviderDebounceTime` | Debounce window in milliseconds on the calls to `pageProvider`            | `number`                                                       | Optional, an integer greater than or equal to 0      |
-| `pageSize`                 | The number of items in a page from the item provider (e.g. a backend API) | `number`                                                       | Required, an integer greater than or equal to 1      |
-| `scrollTo`                 | Scroll to a specific item by index                                        | `number`                                                       | Optional, an integer from 0 to the `length` prop - 1 |
+| Name                       | Description                                                                       | Type                                                           | Validation                                           |
+| -------------------------- |-----------------------------------------------------------------------------------| -------------------------------------------------------------- | ---------------------------------------------------- |
+| `length`                   | The number of items in the list                                                   | `number`                                                       | Required, an integer greater than or equal to 0      |
+| `pageProvider`             | The callback that returns a page of items as a promise. `pageNumber` start with 0 | `(pageNumber: number, pageSize: number) => Promise<unknown[]>` | Required                                             |
+| `pageProviderDebounceTime` | Debounce window in milliseconds on the calls to `pageProvider`                    | `number`                                                       | Optional, an integer greater than or equal to 0      |
+| `pageSize`                 | The number of items in a page from the item provider (e.g. a backend API)         | `number`                                                       | Required, an integer greater than or equal to 1      |
+| `scrollTo`                 | Scroll to a specific item by index                                                | `number`                                                       | Optional, an integer from 0 to the `length` prop - 1 |
 
 Example: