Update whats-new.adoc for 1.0.0 release

Signed-off-by: onobc <[email protected]>

Author: onobc

spring-grpc-docs/src/main/antora/modules/ROOT/pages/whats-new.adoc

@@ -2,10 +2,20 @@
 
 :page-section-summary-toc: 1
 
+[[what-s-new-in-1.0.0-since-0-9-0]]
+== What's New in 1.0.0 Since 0.9.0
+
+This section covers the changes made from version 0.9.0 to version 1.0.0.
+
+* Default stub factory now configurable via properties
+* Update to Spring Boot 4 / Spring Framework 7 and the corresponding Spring Portfolio updates (e.g. Spring Security 6)
+* JSpecify for nullability constraints
+* Java 25 support
+
 [[what-s-new-in-0.9.0-since-0-8-0]]
 == What's New in 0.9.0 Since 0.8.0
 
-This section covers the changes made from version 0.8.0 to version 1.0.0-SNAPSHOT.
+This section covers the changes made from version 0.8.0 to version 0.9.0.
 
 * Upgrade to Spring Boot 3.5.0.
 * `StubFactory` contract changes: the "supports" method is now a static method (it is called before an instance is created).