feat(frontends/lean): use uniform delimiter
feat(frontends/lean): use uniform delimiter

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