Rename `index.md` to `_index.md` for better repository navigation

[qiujuer]

Summary

I would like to propose renaming every index.md file in the repository to _index.md.

Current structure:

path/to/bundle/
├── index.md
├── log.md
├── <concept>.md
└── <subdirectory>/
    ├── index.md
    ├── <concept>.md
    └── <subdirectory>/
        └── …

Proposed structure:

path/to/bundle/
├── _index.md
├── log.md
├── <concept>.md
└── <subdirectory>/
    ├── _index.md
    ├── <concept>.md
    └── <subdirectory>/
        └── …

Motivation

When browsing the repository on GitHub or in most IDEs/editors, files are typically sorted alphabetically.

Using _index.md places the bundle entry file at the top of the directory, making it much easier to:

• Quickly identify the entry document for a bundle.
• Reduce the time spent searching for index.md among many files.
• Improve manual review and repository navigation.
• Provide a more consistent visual structure across all bundle directories.

This is especially helpful in directories containing many concept files, where the entry document is frequently accessed.

Benefits

• Better discoverability of the bundle entry file.
• Improved developer experience when navigating the repository.
• No change to the document contents or organization—only the filename.

If there are no tooling or compatibility constraints requiring the filename to remain index.md, I think _index.md would provide a small but meaningful usability improvement.

Thanks for considering this suggestion!