refactor(emacs/lean-syntax.el): clean up regexps for syntax
refactor(emacs/lean-syntax.el): clean up regexps for syntax

digama0/lean,sp3ctum/lean,leanprover/lean,c-cube/lean,levnach/lean,levnach/lean,fgdorais/lean,fgdorais/lean,avigad/lean,digama0/lean,eigengrau/lean,soonhokong/lean-osx,soonhokong/lean,UlrikBuchholtz/lean,sp3ctum/lean,leodemoura/lean,eigengrau/lean,c-cube/lean,leanprover/lean,digama0/lean,soonhokong/lean-windows,rlewis1988/lean,leanprover-community/lean,johoelzl/lean,Kha/lean,eigengrau/lean,fpvandoorn/lean,avigad/lean,dselsam/lean,digama0/lean,leodemoura/lean,leodemoura/lean,soonhokong/lean,dselsam/lean,soonhokong/lean-windows,avigad/lean,digama0/lean,leanprover/lean,rlewis1988/lean,eigengrau/lean,Kha/lean,fgdorais/lean,johoelzl/lean,soonhokong/lean-osx,soonhokong/lean-windows,rlewis1988/lean,eigengrau/lean,c-cube/lean,soonhokong/lean-windows,avigad/lean,johoelzl/lean,fpvandoorn/lean2,leodemoura/lean,leanprover-community/lean,dselsam/lean,leanprover-community/lean,javra/lean,c-cube/lean,levnach/lean,leanprover-community/lean,digama0/lean,soonhokong/lean,leanprover-community/lean,rlewis1988/lean,avigad/lean,rlewis1988/lean,fgdorais/lean,fpvandoorn/lean,leanprover/lean,UlrikBuchholtz/lean,javra/lean,johoelzl/lean,soonhokong/lean-osx,javra/lean,soonhokong/lean,javra/lean,fgdorais/lean,c-cube/lean,UlrikBuchholtz/lean,UlrikBuchholtz/lean,soonhokong/lean-osx,Kha/lean,UlrikBuchholtz/lean,sp3ctum/lean,leodemoura/lean,leanprover/lean,Kha/lean,Kha/lean,leanprover/lean,soonhokong/lean,dselsam/lean,leodemoura/lean,soonhokong/lean-osx,levnach/lean,fpvandoorn/lean2,fpvandoorn/lean,fpvandoorn/lean,fpvandoorn/lean2,johoelzl/lean,Kha/lean,fpvandoorn/lean,javra/lean,avigad/lean,leanprover-community/lean,levnach/lean,sp3ctum/lean,johoelzl/lean,sp3ctum/lean,fgdorais/lean,rlewis1988/lean,soonhokong/lean-windows,fpvandoorn/lean2,dselsam/lean,fpvandoorn/lean2,dselsam/lean,fpvandoorn/lean