Create an Examples Gallery for LaunchMap

[SakshayMahna]

Goal

It is required to make it easier for new users and contributors to see how LaunchMap works on real ROS 2 launch files. Currently, the best examples live in parser/tests/real_cases/launch_files, but they are hidden inside the test suite.

The goal of this issue is to create a new examples/ gallery at the repo root that showcases curated launch files, their parsed JSON, and screenshots of their visualization.

Acceptance Criteria

• Add a new examples/ folder at the repository root.
• Each example should have:
  • The launch file
  • The parser output JSON.
  • A screenshot (from the VSCode extension visualization).
  • A short README.md explaining what the example demonstrates.
  • Update main README.md to link to the new examples/ folder.

Sub‑Issues (Pick One)

Each of these can be a separate PR (good for new contributors).

• Add TurtleBot4 Bringup example
• Add Nav2 Bringup example
• Add OpaqueFunction example
• Add rrbot example

Notes for Contributors

• The authoritative launch files already exist in parser/tests/real_cases/launch_files.
• Please reuse those files to keep consistency.
• Screenshots can be taken by running the LaunchMap VSCode extension and capturing the visualization view.
• Keep the README.md for each example short and simple, explaining what is shown.