To generate the docs for FlatBuffers from the source files, you will first need to install two programs.
You will need to install doxygen. See Download Doxygen.
You will need to install doxypypy to format python comments appropriately. Install it from here.
Note: You will need both doxygen and doxypypy to be in your PATH environment variable.
After you have both of those files installed and in your path, you need to set up the py_filter to invoke doxypypy from doxygen.
Follow the steps here.
Run the following commands to generate the docs:
cd flatbuffers/docs/source doxygen
The output is placed in flatbuffers/docs/html.
Note: The Go API Reference code must be generated ahead of time. For instructions on how to regenerated this file, please read the comments in GoApi.md.