`peek` documentation example output is outdated/incomplete

[huonw]

Describe the bug

We have docs around the peek goal that include some example output: https://www.pantsbuild.org/2.20/docs/using-pants/project-introspection#peek---programmatically-inspect-a-target

This hasn't been updated for various changes (very easy to forget). For instance, running PANTS_VERSION=2.20.1 pants peek helloworld/greet:tests in https://github.com/pantsbuild/example-python gives:

[
  {
    "address": "helloworld/greet:tests",
    "target_type": "python_tests",
    "dependencies": [
      "helloworld/greet/greeting_test.py:tests"
    ],
    "description": null,
    "overrides": null,
    "skip_black": false,
    "skip_docformatter": false,
    "skip_flake8": false,
    "skip_isort": false,
    "skip_mypy": false,
    "sources": [
      "helloworld/greet/greeting_test.py"
    ],
    "sources_fingerprint": "2158e096d5ab63e537d88067b50a0274b83f6373143faf854d4a9adf5d01cf78",
    "sources_raw": [
      "test_*.py",
      "*_test.py",
      "tests.py"
    ],
    "tags": null
  }
]

This has various differences:

• sources is now the actual file paths
• source_fingerprint is a hash of the above
• sources_raw is new

In 2.21, Running on a single file path has various new fields too, like goals.

Pants version
2.20, 2.21

OS
macOS

Additional info
N/A