Add deprecation notice

Change-Id: Ie0209529fc56a2dc694a97b9e0c7dd7a2ae95e8b

README.md

diff --git a/README.md b/README.md
index f5c3d02..f4e98c3 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,11 @@
-GitHub plugin
+# DEPRECATION NOTICE
+
+GerritForge has decided to [change the license to BSL](https://gitenterprise.me/2025/09/30/re-licensing-gerritforge-plugins-welcome-to-gerrit-enterprise/)
+therefore the Apache 2.0 version of this plugin is deprecated.
+The recommended version of the github plugin is on [GitHub](https://github.com/GerritForge/github)
+and the development continues on [GerritHub.io](https://review.gerrithub.io/admin/repos/GerritForge/github,general).
+
+GitHub plugin (DEPRECATED)
 =============
 This plugin allows existing GitHub repositories to be integrated
 as Gerrit projects.