Document OAuth 2.0 Protected Resource Metadata support

Issue gh-17244

Author: jgrandja

docs/modules/ROOT/nav.adoc

@@ -90,6 +90,7 @@
 **** xref:servlet/oauth2/resource-server/multitenancy.adoc[Multitenancy]
 **** xref:servlet/oauth2/resource-server/bearer-tokens.adoc[Bearer Tokens]
 **** xref:servlet/oauth2/resource-server/dpop-tokens.adoc[DPoP-bound Access Tokens]
+**** xref:servlet/oauth2/resource-server/protected-resource-metadata.adoc[Protected Resource Metadata]
 *** xref:servlet/oauth2/authorization-server/index.adoc[OAuth2 Authorization Server]
 **** xref:servlet/oauth2/authorization-server/getting-started.adoc[Getting Started]
 **** xref:servlet/oauth2/authorization-server/configuration-model.adoc[Configuration Model]

docs/modules/ROOT/pages/servlet/oauth2/resource-server/protected-resource-metadata.adoc

@@ -0,0 +1,28 @@
+[[oauth2resourceserver-protected-resource-metadata]]
+= OAuth 2.0 Protected Resource Metadata
+
+`OAuth2ResourceServerConfigurer.ProtectedResourceMetadataConfigurer` provides the ability to customize the https://www.rfc-editor.org/rfc/rfc9728.html#section-3[OAuth 2.0 Protected Resource Metadata endpoint].
+It defines an extension point that lets you customize the https://www.rfc-editor.org/rfc/rfc9728.html#section-3.2[OAuth 2.0 Protected Resource Metadata response].
+
+`OAuth2ResourceServerConfigurer.ProtectedResourceMetadataConfigurer` provides the following configuration option:
+
+[source,java]
+----
+@Bean
+public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
+	http
+		.oauth2ResourceServer((resourceServer) ->
+			resourceServer
+				.protectedResourceMetadata(protectedResourceMetadata ->
+                    protectedResourceMetadata
+                        .protectedResourceMetadataCustomizer(protectedResourceMetadataCustomizer)   <1>
+				)
+		);
+
+	return http.build();
+}
+----
+<1> `protectedResourceMetadataCustomizer()`: The `Consumer` providing access to the `OAuth2ProtectedResourceMetadata.Builder` allowing the ability to customize the claims of the Resource Server's configuration.
+
+`OAuth2ResourceServerConfigurer.ProtectedResourceMetadataConfigurer` configures the `OAuth2ProtectedResourceMetadataFilter` and registers it with the Resource Server `SecurityFilterChain` `@Bean`.
+`OAuth2ProtectedResourceMetadataFilter` is the `Filter` that returns the https://www.rfc-editor.org/rfc/rfc9728.html#section-3.2[OAuth2ProtectedResourceMetadata response].