DaVinci documentation - set-up of webpages with Sphinx
Created a first example of DaVinci documentation similarly to what was done in Moore. The intent of this MR is to discuss the topics that need to be covered and define a Table Of Contents.
An example of the resulting website can be found here: https://davincidocs.web.cern.ch/index.html
Work towards DPA task https://gitlab.cern.ch/lhcb-dpa/project/-/issues/102.