Add Node.js dropping note to migration

Author: valentinpalkovic

MIGRATION.md

@@ -3,6 +3,7 @@
 - [From version 7.x to 8.0.0](#from-version-7x-to-800)
   - [Implicit actions can not be used during rendering (for example in the play function)](#implicit-actions-can-not-be-used-during-rendering-for-example-in-the-play-function)
   - [Core changes](#core-changes)
+    - [Dropping support for Node.js 16](#dropping-support-for-nodejs-16)
     - [Autotitle breaking fixes](#autotitle-breaking-fixes)
     - [React v18 in the manager UI (including addons)](#react-v18-in-the-manager-ui-including-addons)
     - [Storyshots has been removed](#storyshots-has-been-removed)
@@ -380,6 +381,10 @@ To summarize:
 
 ### Core changes
 
+#### Dropping support for Node.js 16
+
+In Storybook 8, we have dropped Node.js 16 support since it reached end-of-life on 2023-09-11. Storybook 8 supports Node.js 18 and above.
+
 #### Autotitle breaking fixes
 
 In Storybook 7, the file name `path/to/foo.bar.stories.js` would result in the [autotitle](https://storybook.js.org/docs/react/configure/overview#configure-story-loading) `path/to/foo`. In 8.0, this has been changed to generate `path/to/foo.bar`. We consider this a bugfix but it is also a breaking change if you depended on the old behavior. To get the old titles, you can manually specify the desired title in the default export of your story file. For example: