Update getting started walkthrough: sign in CTA, new AI features, keyboard mappings step

[Copilot]

• Simplified description to beginner-friendly language: "Sign in to start using Copilot, your AI coding assistant. Get help writing code, fixing bugs, and building projects faster — all from a simple chat."
• Changed the "Start to Chat" CTA (CopilotCompleteButton) to "Sign In" so all walkthrough states show a consistent "Sign In" button

Original prompt

update the getting started walkthrough with replaced content around "use ai features for free"... instead focus on the new features we introduced like agents and worktrees and cloud and claude harnesses etc. instead of use ai features cta just make it "sign in" or something.

also add an option to import keyboard mapings from other ides after choose your theme step, you can use palceholder functions it doesnt have to work but just mention cursor windsurf etc

The user has attached the following file paths as relevant context:

• src/vs/workbench/contrib/chat/browser/chatStatus/chatStatusDashboard.ts
• .github/copilot-instructions.md
• AGENTS.md

Created from VS Code.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[satoshinakamoto007]

Lol