Feature Idea: Documentation of Project Structure

When browsing Github repositories, I thought it would be a nice feature
if you could annotate the directories of a project with documentation
comments that explain what is inside the specific directory. If this was
possible with Git, then GUIs like Github or Gitlab could include them.
The idea would be based on Java package Javadoc files which make it
possible to document packages, which I usually do to explain the project
structure.
I think it would be great for OSS, because it would be easy for anybody
who browses a public repo to understand the project structure and maybe
participate without having to read through the documentation.

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Best Wishes

Christian Tallner