Remove index.md from PDF

[yezr]

We use mkdocs-with-pdf plugin to create a .pdf of all our documentation. By default, it uses everything in the nav defined in the mkdocs.yaml.

I'd like to exclude the index.md from that .pdf. The mkdocs-with-pdf documentation says to use the excludes_children option to exclude headings from the pdf table of contents. I'm trying to configure to exclude the index.md but it doesn't seem to be picking it up.

@artoonie can you help me exclude that from the .pdf mkdocs creates?