Add MSW version requirement

docs/writing-tests/test-addon.mdx

@@ -41,6 +41,8 @@ Before installing, make sure your project meets the following requirements:
 - A Storybook framework that uses Vite (e.g. [`vue3-vite`](../get-started/frameworks/vue3-vite.mdx), [`react-vite`](../get-started/frameworks/react-vite.mdx), ['sveltekit`](../get-started/frameworks/sveltekit.mdx), etc.), or the [Storybook Next.js framework with Vite](../get-started/frameworks/nextjs.mdx#with-vite)
 - Vitest ≥ 2.1
     - If you're not yet using Vitest, it will be installed and configured for you when you install the addon
+- (optional) MSW ≥ 2.0
+    - If MSW is installed, it must be v2.0.0 or later to not conflict with Vitest's dependency
 
 <If renderer="react">
   <Callout variant="info" icon="ℹ️">