Docs feedback: Maven archetype repo needs access_token parameter in URL

A GitLab Ultimate customer shared in an internal ticket, that our "… endpoint for Maven packages" doc is missing details/example (or a whole section) specific to Maven archetype plugins and archetype-catalog.xml files.

The configuration we suggest leads to warning about No archetype found in remote catalogue in those cases.

The customer found it necessary to append org/catalog/1.0/archetype-catalog.xml?access_token=<PRIVAET_TOKEN>&amp; to the /packages/maven URL:

<repositories>
  <repository>
    <id>archetype</id>
    <url>https://gitlab.example.com/api/v4/projects/PROJECT_ID/packages/maven/org/catalog/1.0/archetype-catalog.xml?access_token=<PRIVAET_TOKEN>&amp;</url>

to get it working. The & specifically was needed because:

maven plugin auto add the "archetype-catalog.xml" as suffix, which we have to ignore.