index is being generated blank

**I'm submitting a...**

- [x] Bug report.

## Bug report ##

**What is the current behavior?**

index.md is being generated empty

**What is the expected behavior?**

index.md should be generated

**Tell us the steps to reproduce the bug, and if possible share a minimal demo of the problem.**

I am using `generate_reference.bat -i` to generate the documentation. The index.md is being generated but it's empty.

You can clone [my repo](https://github.com/db0/godot-card-gaming) and generate docs from it to replicate yourselves.

Start by cloning the linked godot-card-gaming repository and running generate_reference.bat -i to reproduce the empty index.md output. Trace the documentation-generation path that creates index.md and compare it with the generated reference files; done means index.md contains the expected generated documentation.

Written by the indexing model from the issue text.