Document Keberose Dependency Coordinates

Closes gh-18773

Author: rwinch

docs/modules/ROOT/pages/migration/servlet/kerberos.adoc

@@ -0,0 +1,4 @@
+= Kerberos Migrations
+
+For users leveraging Spring Security's Kerberos support, the Maven  and Gradle Coordinates have been changed since the support was moved from an external module into Spring Security.
+See the xref:servlet/authentication/kerberos/introduction.adoc[Keberos documentation] for the new Maven and Gradle coordinates.

docs/modules/ROOT/pages/servlet/authentication/kerberos/introduction.adoc

@@ -3,3 +3,38 @@
 
 Spring Security Kerberos {spring-security-version} is built and tested with JDK 17,
 Spring Security {spring-security-version} and Spring Framework {spring-core-version}.
+
+The dependency coordinates changed with Spring Security 7:
+
+[tabs]
+======
+Maven::
++
+.pom.xml
+[source,xml,subs="verbatim,attributes"]
+----
+<dependencies>
+	<!-- ... other dependency elements ... -->
+	<dependency>
+		<groupId>org.springframework.security</groupId>
+		<artifactId>spring-security-kerberos-core</artifactId>
+	</dependency>
+	<dependency>
+		<groupId>org.springframework.security</groupId>
+		<artifactId>spring-security-kerberos-web</artifactId>
+	</dependency>
+</dependencies>
+----
+
+Gradle::
++
+.build.gradle
+[source,groovy]
+[subs="verbatim,attributes"]
+----
+dependencies {
+	implementation "org.springframework.security:spring-security-kerberos-core"
+	implementation "org.springframework.security:spring-security-kerberos-web"
+}
+----
+======