Ai freshness pass

[alexwolfmsft]

Summary

Review and update metadata, fix some dated code samples.

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Internal previews

📄 File	🔗 Preview link
docs/ai/azure-ai-for-dotnet-developers.md	Develop AI apps with .NET
docs/ai/conceptual/embeddings.md	Embeddings in .NET
docs/ai/conceptual/understanding-openai-functions.md	"Understanding OpenAI Function Calling"
docs/ai/conceptual/understanding-tokens.md	Understand tokens
docs/ai/get-started-app-chat-scaling-with-azure-container-apps.md	Scale Azure OpenAI for .NET chat using RAG with Azure Container Apps
docs/ai/get-started-app-chat-template.md	Get started with the chat using your own data sample for .NET
docs/ai/how-to/content-filtering.md	docs/ai/how-to/content-filtering
docs/ai/index.yml	[linkListType: architecture
docs/ai/quickstarts/quickstart-local-ai.md	Quickstart - Connect to and chat with a local AI using .NET