doc(marketplace): Update the link to the document

[MyvTsv]

• I have performed a self-review of my code.
• I have added tests (when available) that prove my fix is effective or that my feature works.
• I have updated the CHANGELOG with a short functional description of the fix or new feature.
• This change requires a documentation update.

Description

• Update the link to the plugin's documentation in marketplace: https://help.glpi-project.org/doc-plugins/plugins-glpi/credit

Screenshots (if appropriate):