[FEAT] Subpackages should be rendered within the main package in docsgen

[xelaint]

💡 Feature request

Feature Name

Subpackages should be rendered within the main package in docsgen

The Desired Behavior

Subpackages should not be shown as an independent package. They need to be rendered within its main package

Your Use Case

Prior Work

Environment

Daffodil version: X.Y.Z
Angular version: X.Y.Z 

 
For Tooling issues:
- Node version: XX  
- Platform:  

Others: