chore(README.md): don't mention disabled-by-default tcmalloc dependency
chore(README.md): don't mention disabled-by-default tcmalloc dependency

johoelzl/lean,digama0/lean,avigad/lean,fpvandoorn/lean,Kha/lean,leanprover-community/lean,dselsam/lean,leanprover/lean,avigad/lean,rlewis1988/lean,johoelzl/lean,Kha/lean,rlewis1988/lean,fpvandoorn/lean,johoelzl/lean,dselsam/lean,Kha/lean,rlewis1988/lean,leanprover/lean,leanprover/lean,dselsam/lean,leanprover-community/lean,leodemoura/lean,fpvandoorn/lean,digama0/lean,leanprover-community/lean,dselsam/lean,leodemoura/lean,fpvandoorn/lean,dselsam/lean,digama0/lean,leanprover/lean,avigad/lean,johoelzl/lean,leodemoura/lean,leanprover/lean,Kha/lean,avigad/lean,digama0/lean,digama0/lean,johoelzl/lean,fpvandoorn/lean,leanprover-community/lean,avigad/lean,leodemoura/lean,dselsam/lean,leanprover-community/lean,johoelzl/lean,rlewis1988/lean,leanprover/lean,fpvandoorn/lean,leanprover-community/lean,leodemoura/lean,digama0/lean,rlewis1988/lean,rlewis1988/lean,avigad/lean,Kha/lean,leodemoura/lean,Kha/lean