chore: add basic benchmark script

[EvanHahn]

npm run bench will create a million projects and tell you how long it takes.

[achou11]

nice! do you happen to know how the result is so far?

also curious about what other things are worth benchmarking later on e.g. other kinds of channels or implementations of a message channel

[EvanHahn]

I tried running it a few times and on my machine, it's between 800ms and 900ms. Seems pretty fast, about 1.2 million calls per second.

(I imagine that's different on different devices, though!)

[EvanHahn]

also curious about what other things are worth benchmarking later on e.g. other kinds of channels or implementations of a message channel

I agree. I imagine the message channel is the main bottleneck, but that's just a guess.