Polish "Add missing package-info files"

See gh-18632

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/rsocket/package-info.java

@@ -15,6 +15,6 @@
  */
 
 /**
- * Support for Spring Security's RSocket.
+ * Auto-configuration for RSocket support in Spring Security.
  */
 package org.springframework.boot.autoconfigure.security.rsocket;

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/saml2/package-info.java

@@ -15,6 +15,6 @@
  */
 
 /**
- * Support for Spring Security's SAML 2.0.
+ * Auto-configuration for Spring Security's SAML 2.0.
  */
 package org.springframework.boot.autoconfigure.security.saml2;

spring-boot-project/spring-boot-tools/spring-boot-configuration-docs/src/main/java/org/springframework/boot/configurationdocs/package-info.java

@@ -15,6 +15,6 @@
  */
 
 /**
- * Generate documents for configuration properties.
+ * Support for generating documentation of configuration properties.
  */
 package org.springframework.boot.configurationdocs;