Documentation generator



I was searching for a good document generator the needs was to generate code from the formatted comments from source code. Finally found one tool.
But later I just thought that it will be good if somehow will be possible to automaticly generate nice looking documentation from the code at gitLab pages - something similar to javadoc but with multilanguage support.

Do you have such function in gitlab ?
What You think about it ?
It would be awesome specially for open source libraries, source code and documentation generated directly from commited source code will be at one place. And documentation will be all the time up to date