docs: add in a bunch xml:id's
(cherry picked from commit ebc98b049d1928a13ba344d06f07ab407f23af07)
docs: more xml:id's + GA note + rename guvnor to KIE Workbench + reorganize benchmarking chapter
(cherry picked from commit 4df0722749f72ebbaf9fa1955fe0d8a4b430da86)