Broken link in User Management documentation

**Describe the bug**
The User Management documentation page contains a broken link in the `Manage External Data Sources Using Link` tab.

**To Reproduce**
Steps to reproduce the behavior:
1. Go to [Manage External Data Sources Using Link](https://docs.jans.io/stable/janssen-server/usermgmt/#__tabbed_1_3)
2. Click on **Link Guide**
3. The link results in a “page does not exist” error.

**Expected behavior**
The “Link Guide” link should redirect to the correct Link documentation page.

**Screenshots**

**Additional context**
Please verify the affected link and the related Link documentation. Check whether the referenced documentation was moved, renamed, or removed, and update the link to the correct location accordingly.