Docs: Add "React peer dependency is no longer required" section to addon migration guide

docs/addons/addon-migration-guide.md

@@ -34,6 +34,21 @@ Please upgrade your addon to Node.js 18, as support for Node.js 16 has ended.
 
 UI injected into panels, tools, etc. by addons is now rendered with React 18. Also note that the `key` prop is no longer passed to the render function.
 
+### React peer dependency is no longer required
+
+To remove your addon's peer dependency on React, and reduce its install size, do the following:
+
+1. Move `react`, `react-dom` and the globalized Storybook packages from `peerDependencies` to `devDependencies`
+2. Add the list of globalized packages to the `externals` property in the `tsup` configuration, to ensure they are not part of the bundle.
+
+For an example, see [the updates we've made to the addon-kit](https://github.com/storybookjs/addon-kit/pull/60/files#diff-8fed899bdbc24789a7bb4973574e624ed6207c6ce572338bc3c3e117672b2a20). These changes are optional but recommended.
+
+<Callout variant="info"> 
+
+This assumes your addon is using tsup for bundling. If your addon was built with an older version of addon-kit that uses Babel for bundling, you have to first switch to tsup. For guidance, explore these [older changes implemented in the addon-kit](https://github.com/storybookjs/addon-kit/pull/45/files). 
+
+</Callout>
+
 ### @storybook/components deprecations
 
 `Icons` component from `@storybook/components` is now deprecated in favor of [`@storybook/icons`](https://github.com/storybookjs/icons). Additionally, various `Button` component props are also deprecated, with alternatives provided.
@@ -58,6 +73,16 @@ As a workaround, update your documentation to tell users to opt-in to Babel supp
 npx storybook@latest add @storybook/addon-webpack5-compiler-babel
 ```
 
+## Migration Example
+
+[The Addon Kit repository](https://github.com/storybookjs/addon-kit) has been migrated to support Storybook 8.0, and you can use that as a real-world example to guide your migration. The migration incorporates most of the changes listed above, including migrating the package to ESM with `type: module`. Migrating to ESM is not necessary but we recommend it as it simplifes some of the setup. If you follow the ESM migration below and update your export map in `package.json`, you can safely remove any `manager.js`, `preview.js` and `preset.js` files from the root directory.
+
+[This complete diff view](https://github.com/storybookjs/addon-kit/compare/79282986..cf0875f) shows everything changed between 7.0 and 8.0, but not all of it is relevant for your migration. You can specifically focus on:
+
+- [`package.json`](https://github.com/storybookjs/addon-kit/compare/79282986..cf0875f#diff-7ae45ad102eab3b6d7e7896acd08c427a9b25b346470d7bc6507b6481575d519): Updating dependencies, moving to ESM, updating entries
+- [tsup.config.ts](https://github.com/storybookjs/addon-kit/compare/79282986..cf0875f#diff-8fed899bdbc24789a7bb4973574e624ed6207c6ce572338bc3c3e117672b2a20): Updating bundling strategy to take advantage of Storybook globals.
+- [`.storybook/local-preset.js`](https://github.com/storybookjs/addon-kit/compare/79282986..cf0875f#diff-390b53ea479b1ceffcbf31944f644ee23aa9f337b75a8a0ffd815bed50d376cb): Supporting the ESM migration.
+
 ## Releasing
 
 Release a new major version of your addon for Storybook 8.0. We recommend you to continue supporting 7.x with minor or patch versions. We also recommend releasing your own addon using the `next` tag to test it out in projects.