Update CHANGELOG.md

CHANGELOG.md

@@ -1,7 +1,8 @@
 <!--- DO NOT EDIT THIS FILE - IT'S AUTOMATICALLY GENERATED VIA DEVTOOLS --->
 
-## unreleased
+## 4.0.0.alpha1 2022-04-15
 
+See [rom 6.0 upgrade guide](https://github.com/rom-rb/rom/wiki/6.0-Upgrade-Guide).
 
 ### Changed
 
@@ -10,7 +11,7 @@
 - [internal] `indexes` schema DSL is now a plugin called `:schema_indexes` (via #402) (@solnic)
 - [internal] `Gateway#command` is now used to instantiate sql-specific commands (via #402) (@solnic)
 
-[Compare v3.5.0...main](https://github.com/rom-rb/rom-sql/compare/v3.5.0...main)
+[Compare v3.5.0...v4.0.0.alpha1](https://github.com/rom-rb/rom-sql/compare/v3.5.0...v4.0.0.alpha1)
 
 ## 3.5.0 2021-03-26