Add inline comments to auto-generated YAML configs for better developer UX

Issue Type

Enhancement / UX Improvement

Description

Problem
Server YAML configuration files generated by ng_init_resources_server are difficult to understand without consulting external documentation. New users struggle to understand the structure, required fields, and available options, creating unnecessary friction in the onboarding experience.

Motivation:
While building tutorials for #119, I realized that YAML configs are unusable without consulting documentation. This creates a poor developer experience, especially for new users trying to get started quickly.

Current Experience:

# Current generated config (no guidance)
simple_weather_simple_agent:
  responses_api_agents:
    simple_agent:
      entrypoint: app.py
      resources_server:
        type: resources_servers
        name: simple_weather
      model_server:
        type: responses_api_models
        name: policy_model

Proposed Improvement

Add inline comments to generated YAML configs to explain:

• What each field does
• Required vs optional fields
• Common values and examples
• References to related documentation

Example of Improved Config:

# Server ID - unique name used in requests and references
simple_weather_simple_agent:
  # Server type - must be one of: responses_api_models, resources_servers, responses_api_agents
  # These match the 3 top-level folders in NeMo-Gym
  responses_api_agents:
    # Implementation type - must match a folder name inside responses_api_agents/
    simple_agent:
      # Entrypoint - Python file to run (relative to implementation folder)
      entrypoint: app.py
      
      # Resources configuration
      resources_server:
        type: resources_servers               # What type of server to reference
        name: simple_weather                  # Which specific server instance
      
      # Model configuration (uses policy_* variables from env.yaml)
      model_server:
        type: responses_api_models
        name: policy_model                    # References the model server

Benefits:

• Self-documenting: Users understand configs without external docs
• Faster onboarding: Reduce time to first successful agent run
• Fewer errors: Clear guidance prevents common configuration mistakes
• Better discoverability: Users learn about available options inline
• Consistency: All generated configs follow the same documentation pattern

Proposed Acceptance Criteria:

• Update ng_init_resources_server command to add comments
• Add comments to all template YAML files in resources/
• Consider adding validation hints (e.g., "# Valid values: localhost, 0.0.0.0")
• Document the comment conventions for contributors
• Update tutorials (#119) to reference inline YAML comments as primary documentation

Related:
Tutorial 03 - Interacting with Agents in NeMo Gym (where users first encounter configs)
Tutorial 09 - Configuration Management (which explains these concepts)

Start by locating the ng_init_resources_server command and the YAML templates under resources/. Review Tutorial 03, Tutorial 09, and the related issue #119 to align the inline comments and conventions. Done means generated configs and all relevant templates include accurate guidance, contributor conventions are documented, and the tutorials reference the comments.