introduction note about Cypher 25 (#1320)

Author: JPryce-Aklundh

modules/ROOT/pages/introduction/index.adoc

@@ -7,11 +7,17 @@ ifndef::backend-pdf[]
 :description: This section provides an introduction to the Cypher query language.
 endif::[]
 
-Welcome to the Neo4j Cypher Manual. 
+Welcome to the Neo4j Cypher Manual.
 
-Cypher is Neo4j’s declarative query language, allowing users to unlock the full potential of property graph databases. 
+Cypher is Neo4j’s declarative query language, allowing users to unlock the full potential of property graph databases.
 
-The Cypher Manual aims to be as instructive as possible to readers from a variety of backgrounds and professions, such as developers, administrators, and academic researchers. 
+[NOTE]
+This manual covers Cypher 25.
+As of Neo4j 2025.06, all new Cypher features are exclusively added to Cypher 25, while Cypher 5 is frozen.
+For information about how to how to use Cypher 25, see xref:queries/select-version.adoc[].
+For information about new features added to Cypher 25, see xref:deprecations-additions-removals-compatibility.adoc[].
+
+The Cypher Manual aims to be as instructive as possible to readers from a variety of backgrounds and professions, such as developers, administrators, and academic researchers.
 
 If you are new to Cypher and Neo4j, you can visit the link:{neo4j-docs-base-uri}/getting-started/current/cypher-intro/[Getting Started Guide -> Introduction to Cypher] chapter. 
 Additionally, https://graphacademy.neo4j.com/[Neo4j GraphAcademy] has a variety of free courses tailored for all levels of experience.