Add prefix search documentation

Author: Strift

README.md

@@ -1001,6 +1001,26 @@ client.index('myIndex').updateFacetSearch(enabled: boolean): Promise<EnqueuedTas
 client.index('myIndex').resetFacetSearch(): Promise<EnqueuedTask>
 ```
 
+### Prefix search settings <!-- omit in toc -->
+
+#### [Get prefix search settings](https://www.meilisearch.com/docs/reference/api/settings#get-prefix-search-settings)
+
+```ts
+client.index('myIndex').getPrefixSearch(): Promise<PrefixSearch>
+```
+
+#### [Update prefix search settings](https://www.meilisearch.com/docs/reference/api/settings#update-prefix-search-settings)
+
+```ts
+client.index('myIndex').updatePrefixSearch(prefixSearch: PrefixSearch): Promise<EnqueuedTask>
+```
+
+#### [Reset prefix search settings](https://www.meilisearch.com/docs/reference/api/settings#reset-prefix-search-settings)
+
+```ts
+client.index('myIndex').resetPrefixSearch(): Promise<EnqueuedTask>
+```
+
 ### Embedders <!-- omit in toc -->
 
 ⚠️ This feature is experimental. Activate the [`vectorStore` experimental feature to use it](https://www.meilisearch.com/docs/reference/api/experimental_features#configure-experimental-features)