Unless those micro-services are tightly coupled (meaning it wouldn't make sense to download only some of them, and you would only work with all of them), keeping them each in a separate Git repo is recommended.
But you can still reference them as submodule in a parent repo in order to keep track of their state at any given time.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…