docs: document behaviour of customFetch on discovery

Author: panva

docs/interfaces/DiscoveryRequestOptions.md

@@ -13,7 +13,9 @@ Support from the community to continue maintaining and improving this module is
 • `optional` **\[customFetch\]**: [`CustomFetch`](../type-aliases/CustomFetch.md)
 
 Custom [Fetch API](https://developer.mozilla.org/docs/Web/API/Window/fetch) implementation to use for the HTTP Requests
-the client will be making.
+the client will be making. If this option is used, then the same timeout
+value will be assigned to the resolved [Configuration](../classes/Configuration.md) instance for
+use with all its future individual HTTP requests.
 
 #### See
 

src/index.ts

@@ -939,7 +939,9 @@ export function randomDPoPKeyPair(
 export interface DiscoveryRequestOptions {
   /**
    * Custom {@link !fetch Fetch API} implementation to use for the HTTP Requests
-   * the client will be making.
+   * the client will be making. If this option is used, then the same timeout
+   * value will be assigned to the resolved {@link Configuration} instance for
+   * use with all its future individual HTTP requests.
    *
    * @see {@link customFetch}
    */