revamp onboarding instructions
update
refactor the agent setup guide
Updated Trigger a test task run in the Hydra Lab test service (markdown)
Updated Deploy a test agent service (markdown)
Updated Dev Environment Setup (markdown)
Updated Integrate Hydra Lab test center with Microsoft AAD authentication service (markdown)
Updated _Sidebar (markdown)
Created Technical Design (markdown)
Updated Release Notes (markdown)
Updated Test Task Customization (markdown)
Updated How to customize the test task configuration (markdown)
Updated Customize the test task. (markdown)