docs: Link Seller OIDC config to login CSS selectors config (#584)

README.md

@@ -117,6 +117,8 @@ Example:
     },
 ```
 
+In order for Test Suite to be able to log in to your OpenID Connect Provider, you'll need to also configure `broker.loginPagesSelectors` (see [Broker Microservice Configuration](./packages/openactive-broker-microservice/README.md#loginpagesselectors)).
+
 #### Request Headers
 
 Just a set of request HTTP headers which will be used to make booking requests. There are no restrictions on the `requestHeaders` that can be specified.

packages/openactive-broker-microservice/README.md

@@ -114,7 +114,7 @@ These selectors would work for a login page whose HTML looks like:
 <input type="submit" class="btn-primary" value="Submit" />
 ```
 
-**Context**: For Sellers which use OpenID Connect for authorization, Broker needs to acquire these Sellers' tokens in order to authenticate as each of these Sellers. Broker does this by going through [Authorization Code Flow](https://oauth.net/2/grant-types/authorization-code/), loading the Booking System's login page in a headless browser and entering username/password details therein.
+**Context**: For Sellers which use OpenID Connect for authorization (see [Sellers Authentication Configuration](../../README.md#openid-connect) to see how this is configured), Broker needs to acquire these Sellers' tokens in order to authenticate as each of these Sellers. Broker does this by going through [Authorization Code Flow](https://oauth.net/2/grant-types/authorization-code/), loading the Booking System's login page in a headless browser and entering username/password details therein.
 
 ### `opportunityFeedRequestHeaders`