Plan parameter index may link to wrong parameter when there are duplicates

Describe the Bug

The generated markdown documentation for a Puppet plan includes an indexed list of plan parameters that link to parameter entries describing each one. If a parameter has the same name across multiple plans or tasks, the index appears to always link to just the parameter name and therefore to just the first instance of where that parameter is first referenced, which may be in another task or plan.

Expected Behavior

Plan parameter index should link to the plan's parameter references.

Steps to Reproduce

You can see this in a generated REFERENCE.md page from pam_tools.
The puppetlabs::teardown plan has a scaledown_timeout parameter. The link in the parameter list links to the parameter under the delete_k8s_app_resources task instead.

Environment

• Version 2.9.0
• Platform Ubuntu 18.04

Additional Context

Add any other context about the problem here.

Start by generating the markdown documentation for the pam_tools example and inspect the puppetlabs::teardown parameter index alongside the delete_k8s_app_resources task entry. Trace how duplicate parameter names are turned into links, then verify that the plan index points to its own parameter reference rather than the first matching name.