AFAIK there is no way to extends the Hugo with custom functionalities, like generating pages at run time. The only thing that is allowed is to add hooks when generating links, images and heading.
I used it to generated link to the API documentation directly from the Doxygen tags files: https://invent.kde.org/documentation/develop-kde-org/-/blob/.... This is quite verbose but in the end it allows me to do things like this: `[Action](docs:kirigami2;Action)`. This is visible on develop.kde.org, the other big Hugo project in KDE.
I used it to generated link to the API documentation directly from the Doxygen tags files: https://invent.kde.org/documentation/develop-kde-org/-/blob/.... This is quite verbose but in the end it allows me to do things like this: `[Action](docs:kirigami2;Action)`. This is visible on develop.kde.org, the other big Hugo project in KDE.