update readme

[evisdren]

Entire-Checkpoint: 069f0cb7b375

---

Note

Low Risk
Documentation-only updates with no runtime or behavioral impact. Low risk aside from potential user confusion if the README diverges from actual CLI behavior.

Overview
Updates README.md to improve onboarding and conceptual documentation: adds a table of contents, explicit requirements (Git + supported OS + agent prerequisites), and expands Quick Start with go install instructions.

Adds new explanatory sections on how checkpoints are stored/linked (diagram + description), clarifies auto-commit safety wording, and documents support for git worktrees and concurrent sessions. Also appends a dedicated License section.

^{Written by Cursor Bugbot for commit 3737f6f. This will update automatically on new commits. Configure here.}

[Copilot]

Pull request overview

Updates the project README to make onboarding and conceptual understanding of Entire CLI clearer, adding navigation and expanding documentation about checkpoints and strategies.

Changes:

• Added Table of Contents and a Requirements section.
• Expanded Quick Start with a Go install option and improved code block formatting.
• Added conceptual documentation (How It Works diagram, worktrees, concurrent sessions) and a License section.

[Copilot]

@evisdren I've opened a new pull request, #215, to work on those changes. Once the pull request is ready, I'll request review from you.