CMSIS-NN Documentation in HTML format is published online at https://arm-software.github.io/CMSIS-NN.
The version drop-down menu there allows to switch between the documentation provided with offical releases and the latest draft documentation for the main branch.
The documentation source is maintained in Documentation/Doxygen/ folder as a mixture of markdown and doxygen formats. Component source files, templates and examples may also contribute information that gets integrated into the final documentation.
Generating the HTML-formatted documentation from the source is done with gen_doc.sh script:
CMSIS-NN $ ./Documentation/Doxygen/gen_doc.sh
The script expects specific version of doxygen to be installed locally. After successful execution the resulting documentation package is then available in ./Documentation/html/.