support using D1 not also R2

[oligamiq]

Are you willing to create a library using D1 instead of R2?

D1 can be used without registering a credit card and completely eliminate the possibility of being charged a fee.

https://blog.cloudflare.com/building-d1-a-global-database/

[oligamiq]

Here's an implementation I made to try it out.
It is compatible.
oligamiq@e812f6d

[oligamiq]

I understand that deployment may become more complex, but why are we not using listeners provided by services like Supabase or Firebase in the first place? They offer generous free tiers and enable real-time connectivity.