Include www subdomain example in Domain Routing (#30487)

* Include www subdomain example in Domain Routing

* Update comment

Co-authored-by: jj@jjsweb.site <jj@jjsweb.site>

docs/advanced-features/i18n-routing.md

@@ -100,6 +100,8 @@ module.exports = {
 
     domains: [
       {
+        // Note: subdomains must be included in the domain value to be matched
+        // e.g. www.example.com should be used if that is the expected hostname
         domain: 'example.com',
         defaultLocale: 'en-US',
       },
@@ -122,6 +124,7 @@ module.exports = {
 For example if you have `pages/blog.js` the following urls will be available:
 
 - `example.com/blog`
+- `www.example.com/blog`
 - `example.fr/blog`
 - `example.nl/blog`
 - `example.nl/nl-BE/blog`