Fix signals documentation
Fix signals documentation

- update the code generating the doc to recurse in the submodules
- fixes #1668

DirkHoffmann/indico,mic4ael/indico,mic4ael/indico,ThiefMaster/indico,mic4ael/indico,pferreir/indico,mvidalgarcia/indico,OmeGak/indico,indico/indico,ThiefMaster/indico,indico/indico,indico/indico,DirkHoffmann/indico,ThiefMaster/indico,DirkHoffmann/indico,indico/indico,ThiefMaster/indico,mvidalgarcia/indico,pferreir/indico,OmeGak/indico,DirkHoffmann/indico,mvidalgarcia/indico,pferreir/indico,pferreir/indico,mvidalgarcia/indico,mic4ael/indico,OmeGak/indico,OmeGak/indico