guide: Add parentheses to function names in Dbus documentation
guide: Add parentheses to function names in Dbus documentation

This makes it much clearer what they are.

Closes #5460

mareklibra/cockpit,garrett/cockpit,deryni/cockpit,harishanand95/cockpit,larsu/cockpit,SotolitoLabs/cockpit,sgallagher/cockpit,cockpituous/cockpit,moraleslazaro/cockpit,andreasn/cockpit,SotolitoLabs/cockpit,petervo/cockpit,mvollmer/cockpit,Scribery/cockpit,deryni/cockpit,dperpeet/cockpit,harishanand95/cockpit,sgallagher/cockpit,deryni/cockpit,harishanand95/cockpit,vanloswang/cockpit,cockpit-project/cockpit,garrett/cockpit,larsu/cockpit,arilivigni/cockpit,Scribery/cockpit,SotolitoLabs/cockpit,arilivigni/cockpit,michalskrivanek/cockpit,mareklibra/cockpit,stefwalter/cockpit,arilivigni/cockpit,SotolitoLabs/cockpit,andreasn/cockpit,mvollmer/cockpit,stefwalter/cockpit,sgallagher/cockpit,Scribery/cockpit,cockpit-project/cockpit,andreasn/cockpit,andreasn/cockpit,moraleslazaro/cockpit,martinpitt/cockpit,dperpeet/cockpit,mareklibra/cockpit,michalskrivanek/cockpit,harishanand95/cockpit,xhad/cockpit,xhad/cockpit,moraleslazaro/cockpit,michalskrivanek/cockpit,sgallagher/cockpit,cockpit-project/cockpit,cockpituous/cockpit,mareklibra/cockpit,xhad/cockpit,dperpeet/cockpit,mvollmer/cockpit,andreasn/cockpit,mvollmer/cockpit,sgallagher/cockpit,garrett/cockpit,moraleslazaro/cockpit,deryni/cockpit,arilivigni/cockpit,moraleslazaro/cockpit,deryni/cockpit,xhad/cockpit,martinpitt/cockpit,andreasn/cockpit,andreasn/cockpit,michalskrivanek/cockpit,michalskrivanek/cockpit,michalskrivanek/cockpit,cockpit-project/cockpit,cockpituous/cockpit,xhad/cockpit,cockpituous/cockpit,vanloswang/cockpit,deryni/cockpit,stefwalter/cockpit,mvollmer/cockpit,martinpitt/cockpit,stefwalter/cockpit,arilivigni/cockpit,larsu/cockpit,larskarlitski/cockpit,petervo/cockpit,larsu/cockpit,larskarlitski/cockpit,petervo/cockpit,petervo/cockpit,xhad/cockpit,garrett/cockpit,martinpitt/cockpit,sgallagher/cockpit,cockpituous/cockpit,SotolitoLabs/cockpit,xhad/cockpit,vanloswang/cockpit,vanloswang/cockpit,harishanand95/cockpit,mareklibra/cockpit,garrett/cockpit,michalskrivanek/cockpit,Scribery/cockpit,arilivigni/cockpit,stefwalter/cockpit,SotolitoLabs/cockpit,petervo/cockpit,dperpeet/cockpit,petervo/cockpit,larskarlitski/cockpit,vanloswang/cockpit,harishanand95/cockpit,moraleslazaro/cockpit,deryni/cockpit,dperpeet/cockpit,larskarlitski/cockpit,mareklibra/cockpit,sgallagher/cockpit,dperpeet/cockpit,dperpeet/cockpit,petervo/cockpit,harishanand95/cockpit,larskarlitski/cockpit,stefwalter/cockpit,mareklibra/cockpit,larskarlitski/cockpit,Scribery/cockpit,vanloswang/cockpit,cockpit-project/cockpit,larskarlitski/cockpit,moraleslazaro/cockpit,larsu/cockpit,SotolitoLabs/cockpit,cockpituous/cockpit,martinpitt/cockpit,stefwalter/cockpit,larsu/cockpit,Scribery/cockpit,Scribery/cockpit,arilivigni/cockpit,vanloswang/cockpit