docs(rsc): combine canary/experimental and react-server-dom-webpack sections (#942)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: hi-ogawa <4232207+hi-ogawa@users.noreply.github.com>
Co-authored-by: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>

Author: Copilot

packages/plugin-rsc/README.md

@@ -445,9 +445,44 @@ export function Page() {
 }
 ```
 
-### Canary and Experimental channel releases
+### Using React Canary and Experimental versions
 
-See https://github.com/vitejs/vite-plugin-react/pull/524 for how to install the package for React [canary](https://react.dev/community/versioning-policy#canary-channel) and [experimental](https://react.dev/community/versioning-policy#all-release-channels) usages.
+To use React's [canary](https://react.dev/community/versioning-policy#canary-channel) or [experimental](https://react.dev/community/versioning-policy#all-release-channels) versions with `@vitejs/plugin-rsc`, you have two options:
+
+**Option 1: Use preview releases from pkg.pr.new**
+
+You can use preview releases that bundle specific React versions. See [PR #524](https://github.com/vitejs/vite-plugin-react/pull/524) for instructions on installing these preview packages.
+
+**Option 2: Install `react-server-dom-webpack` directly**
+
+By default, `@vitejs/plugin-rsc` includes a vendored version of `react-server-dom-webpack`. However, when `react-server-dom-webpack` is installed in your project's dependencies, the plugin will automatically use it instead. This allows you to:
+
+- Stay up-to-date with the latest React Server Components runtime without waiting for plugin updates
+- Use specific React versions (stable, canary, or experimental)
+
+Simply install the version you need:
+
+```json
+{
+  "dependencies": {
+    "react": "canary",
+    "react-dom": "canary",
+    "react-server-dom-webpack": "canary"
+  }
+}
+```
+
+Or for experimental:
+
+```json
+{
+  "dependencies": {
+    "react": "experimental",
+    "react-dom": "experimental",
+    "react-server-dom-webpack": "experimental"
+  }
+}
+```
 
 ### Using `@vitejs/plugin-rsc` as a framework package's `dependencies`
 
@@ -561,10 +596,6 @@ Note that while there are official npm packages [`server-only`](https://www.npmj
 
 This build-time validation is enabled by default and can be disabled by setting `validateImports: false` in the plugin options.
 
-### `react-server-dom-webpack`
-
-Currently `@vitejs/plugin-rsc` includes a vendored version of `react-server-dom-webpack`. However, when `react-server-dom-webpack` is installed in user project's dependencies, the plugin will automatically use it instead. This allows you to stay up-to-date with the latest React Server Components runtime without waiting for plugin updates.
-
 ## Credits
 
 This project builds on fundamental techniques and insights from pioneering Vite RSC implementations.