Consider changing syntax of :multi

[deg]

Consider changing the vectors into one-element maps:

So, what is now

{:firebase/multi [[:firebase/write {:path ,,,}]
                  [:firebase/push {:path ,,,}]
                  ,,,]}

would become

{:firebase/multi [{:firebase/write {:path ,,,}}
                  {:firebase/push {:path ,,,}}
                  ,,,]}

This will somewhat simplifies generator code in clients.

Ideally, do this with a check for the deprecated form, of course.