feat(src/emacs/lean-syntax.el): add commonly used operators
feat(src/emacs/lean-syntax.el): add commonly used operators

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

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