Docs: Dataflow schematic of Stdb

[website-features]

it would be nice to have a dataflow schematic of how spacetimedb works.
where in the function chains gets the data copied into and from wasm:

• ctx.db.table().column().find()
• ctx.db.table().index().filter()
• ctx.db.table().insert()
• ctx.db.table().column().delete()
• ctx.db.table().column().update()
• ctx.db.table().iter()
• when and where views run.
• how the subscription response get's calculated
• where and how the clog get's written
• how the error rollback works. (do attempted row writes get counted to the energy cost?)
• what runs in it's own thread? what uses more than one core? what shares a core?

and so on
it's basically about how to optimize and write stdb by understanding what is happening with the data inside and outside of wasm.