Update docs for 6.0.x for Grails 7

Author: jamesfredley

README.md

@@ -4,6 +4,8 @@
 
 ## Branches
 
+**6.0.x** Version of the plugin compatible with Grails 7 and Liquibase 4.27
+
 **5.0.x** Version of the plugin compatible with Grails 6 and Liquibase 4.19
 
 **4.0.x** Version of the plugin compatible with Grails 5 and Liquibase 4.6
@@ -31,6 +33,7 @@ One popular approach is to have a root changelog named changlog.groovy (or chang
 * 3.x: Grails 3 with Hibernate 5
 * 4.0.x Grails 5
 * 5.0.x Grails 6
+* 6.0.x Grails 7
 
 ## Documentation
 * Latest https://grails.github.io/grails-database-migration/latest/
@@ -39,6 +42,7 @@ One popular approach is to have a root changelog named changlog.groovy (or chang
 * Grails 3/4 (Hibernate 5): https://grails.github.io/grails-database-migration/3.0.x/index.html
 * Grails 5 (Hibernate 5): https://grails.github.io/grails-database-migration/4.0.x/index.html
 * Grails 6 (Hibernate 5): https://grails.github.io/grails-database-migration/5.0.x/index.html
+* Grails 7 (Hibernate 5): https://grails.github.io/grails-database-migration/6.0.x/index.html
 * Snapshot: https://grails.github.io/grails-database-migration/snapshot/index.html