Address several user experience issues

[ultmaster]

This pull request introduces enhancements to documentation, new example files demonstrating POML features, and updates to the codebase to improve usability and functionality. The most important changes include updates to the README.md for better clarity, the addition of several POML examples showcasing diverse use cases, and improvements to the Visual Studio Code extension and CLI commands for better configuration handling.

Documentation Updates:

• README.md: Updated instructions for installing the Visual Studio Code extension and added details on configuring language model settings.
• examples/README.md: Added an overview of the POML example library, organized examples by difficulty, and provided guidelines for contributing.

New POML Examples:

Beginner examples:

• examples/101_explain_character.poml: Demonstrates structured prompting with roles, tasks, and multimedia inputs for educational purposes.
• examples/102_render_xml.poml: Provides a template for legacy system migration analysis using XML syntax.

Intermediate examples:

• examples/201_orders_qa.poml: Implements a chatbot agent for customer order queries, integrating data from CSV files.
• examples/202_arc_agi.poml: Tests reasoning capabilities of an LLM by mapping input grids to output grids using JSON data.

Advanced examples:

• examples/301_generate_poml.poml: Combines multiple POML files into JavaScript functions for modular prompt generation.

Codebase Enhancements:

Visual Studio Code extension:

• packages/poml-vscode/command/testCommand.ts: Added validation to ensure language model settings are configured before testing prompts, improving error handling.

CLI improvements:

• packages/poml/cli.ts: Added a cwd option to specify the working directory, enhancing flexibility for file-based operations.

[Copilot]

Pull Request Overview

This PR addresses several user experience issues by improving file path resolution, adding asynchronous finalization in tests, and enhancing language model settings verification. Key changes include:

• Enhancements to file handling using an optional working directory (cwd) in the CLI and index functions.
• Addition of a finalizer in tests to support lingering async operations and improved language model settings checks in the VS Code command.
• New and updated examples in the examples folder, including one incomplete function in the 301_generate_poml.poml file.

Reviewed Changes

Copilot reviewed 21 out of 30 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/poml/tests/index.test.tsx	Added fs/path imports, afterAll finalizer, and dynamic test generation for examples compilation.
packages/poml/index.ts	Introduced cwd support for working directory resolution and updated file path handling.
packages/poml/cli.ts	Added a new cwd option in the CLI arguments.
packages/poml-vscode/command/testCommand.ts	Added language model settings verification with error reporting.
examples/*	Various updates including new assets, JSON/CSV data changes, and updated POML examples (one incomplete function noted).
README.md	Revised installation instructions and configuration guidance.

[Copilot]

The implementation of the 'storyteller' function appears incomplete. Consider providing a proper return value or implementation to prevent unexpected runtime behavior.

Suggested change

	return
	return {{storyteller.replace(/^/gm, ' ').trimStart()}};