Polish index

- Relates #166

Author: jvalkeal

spring-security-kerberos-docs/modules/ROOT/pages/index.adoc

@@ -1 +1,4 @@
-= Spring Security Kerberos - Reference Documentation
+= Spring Security Kerberos
+
+Spring Security Kerberos is an extension of Spring Security for
+application developers to Kerberos concepts with Spring.

spring-security-kerberos-docs/modules/ROOT/pages/introduction.adoc

@@ -1,19 +1,5 @@
 [[introduction]]
 = Introduction
 
-Spring Security Kerberos is an extension of Spring Security for
-application developers to Kerberos concepts with Spring.
-
-== Requirements
-
 Spring Security Kerberos {version} is built and tested with JDK 17,
 Spring Security {spring-security-version} and Spring Framework {spring-version}.
-
-[IMPORTANT]
-====
-Java 8 Update 40/45 had a regression which broke handling of Kerberos tokens.
-These Java versions are no longer supported.
-See https://bugs.openjdk.java.net/browse/JDK-8078439[JDK-8078439] for further
-information.
-====
-