update examples to new SDK

[miwialex]

examples updated to new SDK

[cal-smith]

LGTM, two nits

[cal-smith]

We'll probably want to pin these explicitly, demonstrating good security practices and all that

[cal-smith]

Wording nit

Suggested change

	Any call to `task({ name: ... }, handler)` registers a runnable workflow task.
	`task(...)` returns a task definition, which is not callable on its own — pass
	it to `ctx.step` to run it.
	Any call to `task({ name: ... }, handler)` registers a workflow task and
	returns a task definition, which is not callable on its own. pass it to
	`ctx.step` to run it.