chore(emacs/lean-syntax): highlight 'import/section/end/namespace/open' arguments
chore(emacs/lean-syntax): highlight 'import/section/end/namespace/open' arguments

Signed-off-by: Leonardo de Moura <7610bae85f2b530654cc716772f1fe653373e892@microsoft.com>

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