Switch to repo.packagist.org in docs

src/Packagist/WebBundle/Resources/views/ApiDoc/index.html.twig

@@ -156,7 +156,7 @@ GET https://{{ packagist_host }}/search.json?q=[query]&type=symfony-bundle
 </p>
 
 <pre>
-GET https://{{ packagist_host }}/p/[vendor]/[package].json
+GET https://repo.{{ packagist_host }}/p/[vendor]/[package].json
 <code>
 {
   "packages": {
@@ -174,7 +174,7 @@ GET https://{{ packagist_host }}/p/[vendor]/[package].json
   }
 }
 </code></pre>
-<p>Working example: <code><a href="https://{{ packagist_host }}/p/monolog/monolog.json">https://{{ packagist_host }}/p/monolog/monolog.json</a></code></p>
+<p>Working example: <code><a href="https://repo.{{ packagist_host }}/p/monolog/monolog.json">https://repo.{{ packagist_host }}/p/monolog/monolog.json</a></code></p>
 
 <h4 id="get-package-by-name">Using the API</h4>