Seperate files inside post directory to help organization

[sonukuldeep]

Is your feature request related to a problem? Please describe.
At present only a single file is allowed inside posts/post_name/index.md. Is it possible to have other files inside this post_name folder to help organize the documentation better? Like the index.md page becomes the parent and all sub files become children.

Describe the solution you'd like
In the front matter we could have a variable set to declare a file as parent. This files gets displayed. Other files have a variable that describes them as children. These files do not get rendered directly instead they get rendered inside the parent when imported somehow.