chore: add 'Google ADK' to valid frontmatter tags

[teetangh]

Summary

Adds 'Google ADK' to the valid tags list in test/test-markdown-frontmatter.js.

This is needed for the Google ADK + Couchbase MCP Server tutorial being added in couchbase-examples/mcp-cookbook#3. The tutorial's frontmatter.md uses the Google ADK tag, and the mcp-cookbook CI runs the frontmatter validation from this repo — which currently rejects the tag as invalid.

Change

One line: append 'Google ADK' to the tags array on line 10.

Test plan

• Verified locally that the tag matches the frontmatter.md in mcp-cookbook PR updated tutorial for iOS Sync to show how to use Docker Compose #3

[gemini-code-assist]

Code Review

This pull request adds the 'Google ADK' tag to the tags array in test/test-markdown-frontmatter.js. Feedback suggests reformatting the array into a multi-line, alphabetically sorted list to improve maintainability and identifies 'Google ADK' as a potential typo for 'Google SDK' or 'Google AI SDK'.

[gemini-code-assist]

The tags array is extremely long (over 1,500 characters), which makes it difficult to maintain and results in unreadable git diffs. Formatting it as a multi-line, alphabetically sorted array significantly improves readability and ensures that future additions or removals are clearly visible in diffs. Additionally, the tag 'Google ADK' appears to be a typo for 'Google SDK' or 'Google AI SDK', as 'ADK' typically refers to the Android Accessory Development Kit, which is unrelated to the Model Context Protocol (MCP) mentioned in the PR description.

const tags = [
  '.NET',
  'Ag2',
  'Airbyte',
  'Amazon Bedrock',
  'Android',
  'App Services',
  'Artificial Intelligence',
  'ASP.NET',
  'Authentication',
  'Autogen',
  'AWS',
  'Best Practices',
  'C++',
  'C++ SDK',
  'Cohere',
  'Community Edition',
  'Composite Vector Index',
  'Configuration',
  'Connector',
  'Couchbase Columnar',
  'Couchbase Edge Server',
  'Couchbase ORM',
  'CrewAI',
  'Custom Queries',
  'Customer',
  'Data API',
  'Data Ingestion',
  'Data Modeling',
  'DBaaS',
  'Deepseek',
  'Docker',
  'Express',
  'FastAPI',
  'Flask',
  'Flutter',
  'FTS',
  'Gin Gonic',
  'Google ADK',
  'Google Data Studio',
  'Google Gemini',
  'GraphQL',
  'GSI',
  'Haystack',
  'Hugging Face',
  'Hyperscale Vector Index',
  'Installation',
  'iOS',
  'Jina AI',
  'Kafka',
  'Keycloak',
  'Ktor',
  'LangChain',
  'LangGraph',
  'Laravel',
  'linq',
  'LlamaIndex',
  'LLama3',
  'Looker Studio',
  'mastra',
  'Metadata',
  'Metrics',
  'Mistral AI',
  'Model Context Protocol (MCP)',
  'Monitoring',
  'Next.js',
  'Nvidia NIM',
  'Observability',
  'OpenAI',
  'OpenID',
  'OpenRouter',
  'Optimization',
  'Ottoman',
  'P2P',
  'Prometheus',
  'PydanticAI',
  'Query Workbench',
  'Ragas',
  'Rails',
  'REST API',
  'Search Vector Index',
  'Semantic Kernel',
  'smolagents',
  'Spring Boot',
  'Spring Data',
  'SQL++ (N1QL)',
  'Streamlit',
  'Support',
  'TAVs',
  'TLS',
  'Transactions',
  'UIKit',
  'Xamarin',
  'Xcode'
]