propTypes.exact description not being created on docstrings in specific cases

Describe your context
Please provide us your environment, so we can easily reproduce the issue.

• replace the result of pip list | grep dash below

dash                            2.0.0     
dash-design-kit                 1.6.4  
dash-pro-components             0.0.6   

Describe the bug

When creating a new Dash component, some of propTypes comments are not beeing passed to the component docstrings.
For example, the pro.FlowChart component contains the elements definitions with an array of two exact elements, as shown in the screenshots.
Each one of these exact elements have their own description (e.g: Nodes definitions).
These descriptions are ignored when docstrings are auto-generated even though they are in the metadata.json.

Proptypes example mapped to metadata.json

Looking at _py_components_generation.py, where the py docstrings are beeing generated, we have this function that maps the exact | shape propTypes

This function seems to be ignoring the case that there is a description for the first level of an exact | shape since it iterates through and enters the dictionary levels from the value keys, so never "creates a doc" to the first level description, which is the case of an array of exacts | shapes with a description for each array element

Expected behavior
The expected behavior is that the comments like "Nodes definitions" should be passed to the component docstring.

Start by reading dash/development/_py_components_generation.py around line 494, especially the function that maps exact and shape propTypes. Compare its handling of the metadata.json example with the generated component docstrings; done means descriptions such as “Nodes definitions” appear in the relevant docstrings.