Since luc.lino-framework.org/blog/2017/0203.html

The renaming of invoke command initdb_demo to prop has broken the docs, since python mange initdb_demo has also been changed to prep.

Once possible solution, rather than going through the docs and fixing it, is to create an alias or rename the mange.py initdb_demo command to prep as well, currently looking into it, but can't seem to see where these commands are definded.