chore(docs): Extend the options for custom server init (#52851)

## For Contributors

### Improving Documentation

While working with a custom server, I noticed that [the list of available options within the codebase](https://github.com/vercel/next.js/blob/canary/packages/next/src/server/base-server.ts#L138-L180) was much larger than [the options listed within the docs](https://nextjs.org/docs/pages/building-your-application/configuring/custom-server). This PR extends the `next` import function options to include all of ~the allowed~ documented options from the codebase. 

- [x] Run `pnpm prettier-fix` to fix formatting issues before opening the PR.
- [x] Read the Docs Contribution Guide to ensure your contribution follows the docs guidelines: https://nextjs.org/docs/community/contribution-guide




Co-authored-by: Lee Robinson <9113740+leerob@users.noreply.github.com>

docs/03-pages/01-building-your-application/06-configuring/10-custom-server.mdx

@@ -88,10 +88,16 @@ const app = next({})
 
 The above `next` import is a function that receives an object with the following options:
 
-- `dev`: `Boolean` - Whether or not to launch Next.js in dev mode. Defaults to `false`
-- `dir`: `String` - Location of the Next.js project. Defaults to `'.'`
-- `quiet`: `Boolean` - Hide error messages containing server information. Defaults to `false`
-- `conf`: `object` - The same object you would use in [next.config.js](/docs/pages/api-reference/next-config-js). Defaults to `{}`
+| Option         | Type               | Description                                                                                                   |
+| -------------- | ------------------ | ------------------------------------------------------------------------------------------------------------- |
+| `conf`         | `Object`           | The same object you would use in [next.config.js](/docs/pages/api-reference/next-config-js). Defaults to `{}` |
+| `customServer` | `Boolean`          | (_Optional_) Set to false when the server was created by Next.js                                              |
+| `dev`          | `Boolean`          | (_Optional_) Whether or not to launch Next.js in dev mode. Defaults to `false`                                |
+| `dir`          | `String`           | (_Optional_) Location of the Next.js project. Defaults to `'.'`                                               |
+| `quiet`        | `Boolean`          | (_Optional_) Hide error messages containing server information. Defaults to `false`                           |
+| `hostname`     | `String`           | (_Optional_) The hostname the server is running behind                                                        |
+| `port`         | `Number`           | (_Optional_) The port the server is running behind                                                            |
+| `httpServer`   | `node:http#Server` | (_Optional_) The HTTP Server that Next.js is running behind                                                   |
 
 The returned `app` can then be used to let Next.js handle requests as required.