I was wondering what did you use to create the allegro documentation ?
Since allegro's documentation is verry good..

https://pandoc.org/

Yes, pandoc, together with naturaldocs: http://www.naturaldocs.org/

I think only A4 docs used naturaldocs, A5 is pandoc only. This is the build files to create them (I don't claim to fully understand all the steps): https://github.com/liballeg/allegro5/blob/master/docs/CMakeLists.txt

You are right, we don't use naturaldocs anymore. But we do compile a version of dawk to do some text processing.