Merge pull request #7571 from dhensby/pulls/4.0/didnt-they-tell-you-4-is-stable

DOCS Update 4.0.0 changelog to indicate stable release

docs/en/04_Changelogs/4.0.0.md

@@ -1,4 +1,4 @@
-# 4.0.0 (unreleased)
+# 4.0.0
 
 ## Introduction
 
@@ -81,7 +81,6 @@ Backup your existing `composer.json` and overwrite it with the following content
 This composer file uses the new [recipe](https://github.com/silverstripe/recipe-plugin) approach
 which bundles all core dependencies in a meta package. If you want more granular control over what gets installed,
 check the `composer.json` files in [recipe-core](https://github.com/silverstripe/recipe-core) and [recipe-cms](https://github.com/silverstripe/recipe-cms).
-Since this is a pre-release, you need to allow composer to install unstable dependencies via `minimum-stability: dev`.
 
 Now run a `composer update`. This will remove all existing modules from your local codebase
 since we replaced your project's `composer.json`. Now you can move back your modules
@@ -488,6 +487,7 @@ For instance, code which logs errors should be upgraded as below:
 ```diff
 -SS_Log::log('My error message', SS_Log::ERR);
 +use Psr\Log\LoggerInterface;
++use SilverStripe\Core\Injector\Injector;
 +Injector::inst()->get(LoggerInterface::class)->error('My error message');
 ```