Trying to link to a nested module causes broken links

Problem Description

I have a package with several nested modules. I wanted to refer to them by their names, without prefixing the package name, so I used a [nested](module.nested) Markdown link. This broke link generation.

Steps to reproduce the behavior:

Create module/. Inside it:

# module/__init__.py
"""
[nested](module.nested)
"""

# module/nested.py
"""Hello there"""

This generates the following HTML:

<div class="docstring">
  <p>
    <a href="<a href=" module="" nested.html"="">module.nested</a>"&gt;nested
  </p>
</div>

System Information

$ pdoc --version
pdoc: 15.0.3
Python: 3.12.10
Platform: Linux-6.12.28-0-lts-x86_64-with

Start by reproducing the issue with module/init.py linking to module.nested and module/nested.py, then inspect pdoc's Markdown link generation using the malformed HTML as the failure signal. Done means the nested link renders as a valid anchor pointing to the nested module without duplicated or broken markup.