Use alectryon to generate doc with proof state

Let's use this awesome tool: https://github.com/cpitclaudel/alectryon

While at it, also update the CI configuration to minimize the jobs that run in wip- branches.

scripts/Makefile.alectryon

+alectryon: $(GLOBFILES) $(VFILES)
+	$(SHOW)'Running alectryon on all .v files'
+	$(HIDE)scripts/alectryon.sh $(VFILES)
+