feat: add --version CLI command

[janmatzek]

JIRA: trivial

Summary by CodeRabbit

• New Features

  • Added a --version option to the CLI so you can quickly check the installed tool version.
  • The CLI now shows a version number when the package is installed, with a clear fallback message if version info isn’t available.

• Documentation

  • Updated the installation instructions with a command to verify the CLI version after setup.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: fd771e7f-8ad7-4bae-a1d5-112b803a7cf0

📥 Commits

Reviewing files that changed from the base of the PR and between 4b6a532 and 59cd37b.

📒 Files selected for processing (2)

• README.md
• src/gooddata_legacy2cloud/arg_parsing/cli_commands.py

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📝 Walkthrough

Walkthrough

This PR adds a --version CLI flag to gooddata-legacy2cloud. It computes __version__ via importlib.metadata.version, falling back to a placeholder string if package metadata is unavailable, wires this into argparse, and documents the new flag in the README.

Changes

CLI Version Flag

Layer / File(s)	Summary
Version lookup and CLI flag wiring src/gooddata_legacy2cloud/arg_parsing/cli_commands.py, README.md	Adds importlib.metadata imports, computes __version__ with a PackageNotFoundError fallback, adds a --version argparse flag, and documents version checking in the README.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Poem

A rabbit hops with version in tow,
"--version" now tells you what you know,
No more guessing which build you run,
One flag, one hop, the job is done! 🐇✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly matches the main change: adding a --version CLI command.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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_{Comment @coderabbitai help to get the list of available commands.}