This PR enhances the validator command with JSON output capabilities and additional data inclusion options.

New Features

• JSON output to stdout: Use -o - to write JSON validation results directly to stdout, which automatically enables quiet mode
• Quiet mode: New -q/--quiet flag to suppress log output, useful for scripting and CI pipelines
• Extended JSON output options:
  • --include-entities - Include GTFS entities in JSON output
  • --include-route-geometries - Include route geometries in JSON output
  • --include-service-levels - Include service levels in JSON output

Changes

• Renamed output flag from --o to -o/--out for consistency with CLI conventions
• Improved help text with usage examples showing the new functionality

Example Usage

# Output JSON to stdout with entities included
transitland validate -o - --include-entities "http://developer.trimet.org/schedule/gtfs.zip"

# Write JSON to file with all extras
transitland validate -o report.json --include-entities --include-route-geometries --include-service-levels gtfs.zip

# Validate with quiet mode (logs suppressed)
transitland validate -q "https://www.bart.gov/dev/schedules/google_transit.zip"

Motivation

These changes make it easier to programmatically consume validation results by:

1. Allowing JSON output to stdout for piping to other tools
2. Suppressing log messages that would interfere with JSON parsing
3. Providing optional inclusion of additional data (entities, geometries, service levels) in the output