apt install python3-sphinx python3-sphinx-rtd-theme
Changes are made in the .rst files at sphinx/source
After editing the HTML sites have to be generated.
sphinx-build ./sphinx/source/ openatlas/static/manual
After finishing changes it is a good practice to delete the openatlas/static/manual directory and generate the whole manual again. Otherwise not all changes (e.g. menu structure) may be propagated correctly.