Add Worker snippets for the SDK Worker pages

[lennessyy]

What

Adds snippet regions to features/snippets/worker/ for the per-SDK Run a Worker documentation pages.

New snippet IDs:

	Go	Python	TypeScript
Create and run	—	python-create-worker	—
Versioned Worker	go-versioned-worker	python-versioned-worker	typescript-versioned-worker
Graceful shutdown	—	python-worker-graceful-shutdown	typescript-worker-graceful-shutdown

Why

The run-worker-process docs pages currently use hand-written inline code, and none of the eight SDK Worker pages document a versioned Worker at all. These snippets give those pages a compile-checked source.

Go and TypeScript pull their create-and-run snippet from the hello-world samples instead, so only Python needs one here — its hello sample runs the client inside the Worker's async with block, so there's no clean region to mark.

Notes

• Placeholder Workflow and Activity names follow the existing snippets/plugins convention: HelloWorkflow, some_activity.
• Markers stay tight around the Worker construction, matching the existing *-worker-max-cached-workflows snippets in these files.
• worker.go also picks up a trailing newline it was missing.

Verification

• go build ./snippets/worker/ passes against SDK v1.45.0.
• Python API names verified by introspecting an installed temporalio: deployment_config and graceful_shutdown_timeout are real Worker params, and the WorkerDeploymentConfig / WorkerDeploymentVersion field names match.
• TypeScript checked against the published 1.18.1 declarations: workerDeploymentOptions exists, shutdownGraceTime accepts an ms-formatted string, and defaultVersioningBehavior is required when useWorkerVersioning: true. I did not run tsc locally, so CI is the real check there.