Add Semantic Kernel Pivot to Open AI Quick Starts

[JakeRadMSFT]

Summary

This PR is to add SK (Semantic Kernel) pivots for the code sections in the AI Quick Starts.

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Internal previews

📄 File	🔗 Preview link
docs/ai/quickstarts/get-started-azure-openai.md	CustomerIntent: As a .NET developer new to Azure OpenAI, I want deploy and use sample code to interact to learn from the sample code.
docs/ai/quickstarts/quickstart-ai-chat-with-data.md	Get insight about your data from an .NET Azure AI chat app
docs/ai/quickstarts/quickstart-azure-openai-tool.md	Extend Azure AI using Tools and execute a local Function with .NET
docs/ai/quickstarts/quickstart-openai-generate-images.md	Quickstart - Generate images using Azure AI with .NET
docs/ai/quickstarts/quickstart-openai-summarize-text.md	CustomerIntent: As a .NET developer new to Azure OpenAI, I want deploy and use sample code to interact to learn from the sample code to summarize text.

[aaronpowell]

I think the order of setting up the secrets and using the Chat/Image services is backwards, as you set that up before getting the keys, so if you copy the code in as it stands it won't compile.

Given that there's repeated steps across each of them (setting up the secrets), should we pull that out as an include so we can have that referenced into each article rather than copy/pasted?

[luisquintanilla]

LGTM.