Content set extensions.

The documentation engineering team will on occasion built extensions for specific use-cases.

These extension needs to be explicitly opted into since they typically only apply to a few content sets.

For the TRADE team the team built in support to picking up detection rule files from the source and emitting
documentation and navigation for them.

To enable:

extensions:
  - detection-rules

This now allows you to use the special detection_rules instruction in the Table of Contents
As a means to pick up toml files as children

toc:
  - file: index.md
    detection_rules: '../rules'