Add documentation for new migrate Cloudflare CLI command (#205)

Author: dario-piotrowicz

pages/cloudflare/cli.mdx

@@ -8,7 +8,7 @@ The Cloudflare adapter provides a `opennextjs-cloudflare` CLI to develop, build,
 
 `opennextjs-cloudflare` support multiple commands, invoked via `opennextjs-cloudflare <command>`.
 
-The currently supported commands are `build`, `populateCache`, `preview`, `deploy`, and `upload`.
+The currently supported commands are `build`, `populateCache`, `preview`, `deploy`, `upload`, and `migrate`.
 
 You can list the commands by invoking `pnpm opennextjs-cloudflare` and get help with a given command by invoking `pnpm opennextjs-cloudflare <command> --help`.
 
@@ -47,3 +47,30 @@ It starts by populating the remote cache and then deploys your application to Cl
 ### `upload` command
 
 It starts by populating the remote cache and then uploads a version of your application to Cloudflare (via `wrangler upload`). Note that the application will not automatically be served on uploads. See [Gradual deployments](https://developers.cloudflare.com/workers/configuration/versions-and-deployments/gradual-deployments/) to learn more about how to serve an uploaded version.
+
+### `migrate` command
+
+Converts a standard Next.js project into an OpenNext-compatible one. This command automates the setup steps described in the [Get Started guide](/cloudflare/get-started#existing-nextjs-apps), including:
+
+- Installing required dependencies (`@opennextjs/cloudflare` and `wrangler`)
+- Creating a `wrangler.jsonc` configuration file
+- Creating an `open-next.config.ts` file
+- Adding a `.dev.vars` file
+- Updating the `package.json` scripts
+- Adding static asset caching headers (`public/_headers`)
+- Adding `.open-next` to `.gitignore`
+- Setting up local development with `initOpenNextCloudflareForDev()` in your Next.js config
+
+Additionally, the command creates an R2 bucket and configures it for caching.
+
+<Callout type="info">
+  The R2 bucket for caching is only created if R2 is enabled on your Cloudflare account. If R2 is not enabled,
+  no caching setup is performed by the migrate command. See the [Caching docs](/cloudflare/caching) for
+  information on manually configuring caching.
+</Callout>
+
+Run the command in your existing Next.js project:
+
+```sh
+npx @opennextjs/cloudflare migrate
+```

pages/cloudflare/get-started.mdx

@@ -12,6 +12,16 @@ npm create cloudflare@latest -- my-next-app --framework=next --platform=workers
 
 #### Existing Next.js apps
 
+The easiest way to convert an existing Next.js app is to use the `migrate` command:
+
+```sh
+npx @opennextjs/cloudflare migrate
+```
+
+This command automates all the setup steps below. If R2 is enabled on your account, it also creates an R2 bucket for caching. See the [CLI documentation](/cloudflare/cli#migrate-command) for more details.
+
+Alternatively, you can follow the manual steps below.
+
 ##### 1. Install @opennextjs/cloudflare
 
 First, install [@opennextjs/cloudflare](https://www.npmjs.com/package/@opennextjs/cloudflare):