Link to GitLab documentation for auth (#9833)

Co-authored-by: Jordi Boggiano <j.boggiano@seld.be>

doc/articles/authentication-for-private-packages.md

@@ -223,7 +223,10 @@ composer config [--global] --editor --auth
 > **Note:** For the gitlab authentication to work on private gitlab instances, the
 > [`gitlab-domains`](../06-config.md#gitlab-domains) section should also contain the url.
 
-When creating a gitlab token manually, make sure it has either the `read_api` or `api` scope.
+To create a new access token, go to your [access tokens section on GitLab](https://gitlab.com/-/profile/personal_access_tokens)
+(or the equivalent URL on your private instance) and create a new token. See also [the GitLab access token documentation](https://docs.gitlab.com/ee/user/profile/personal_access_tokens.html#creating-a-personal-access-token) for more informations.
+
+When creating a gitlab token manually, make sure it has either the `read_api` or `api` scope. 
 
 ### Command line gitlab-token