Include header file documentation

[roximn148]

To enhance usability, it would be beneficial to include the corresponding header file name in the documentation for each section. That would make it much easier for users to find and include the correct header files, instead of having to guess.

For example,

[frang75]

Hi @roximn148,
Yes its a good tip. I will include this in feature ndoc for next documentation version.

[frang75]

Added Header info in NAppGUI docs