The static version of the Cadabra web site is located in
the 

   cadabra2/build

directory. This web site is built using 'Clay', available from

   http://lucuma.github.io/Clay/

and installable with

   pip install clay

You also need

   sudo apt install doxygen

Clay builds the static site from the template files in
cadabra2/source. To do this, 

   cd cadabra2
   clay build 

or use the built-in web server which does this on-the-fly,

   cd cadabra2
   clay run