An introduction to Worker tuning

What this post added

This post provides foundational knowledge for deploying and managing Worker Pools, focusing on performance tuning Worker-side code. It discusses key metrics like `workflow_task_schedule_to_start_latency` and `worker_task_slots_available` to determine when to scale Workers up or down. It also details configurations like `MaxConcurrentActivityExecutionSize` and `MaxConcurrentWorkflowTaskExecutionSize`.