What is the use case of leaf bundle, especially when it contains other .md files?

Hi, I am a newbie to Hugo and I’ve been struggling with index.md feature recently.
Basically, I found out when there is an index.md file in a folder, other .md files would not be shown/rendered on the site.
Then I found that it is the effect of the leaf bundle, as the doc stated.

However, I am wondering what is the use case of this feature?
Like the example in official documentation: https://gohugo.io/content-management/page-bundles/#examples-of-leaf-bundle-organization

my-post
This leaf bundle has the index.md , two other content Markdown files and two image files.

Especially, how can you actually add the “other content Markdown files” into index.md, when they are not rendered at all?

Hi

rename index.md to _index.md and then leave it alone

Then the other .md files will be ok

Alternative - look in the examplesite folder for the theme you are using and copy that structure