docs: fixes licensing code example

docs/production/licensing.mdx

@@ -13,7 +13,7 @@ Payload is free to use locally for development purposes for as long as you like.
 1. Complete the [checkout](/checkout) process. You'll be provided with a license key after successfully checking out.
 1. Add your license to a `.env` variable, and then add the `license` property to your `payload.init()` call.
 
-`payload.config.js`:
+`server.js`:
 ```js
 const payload = require('payload');