[WIP] IA: Develop and Deploy

[sfc-gh-dmatthews]

📚 Context

For the next phase of reworking information architecture, Streamlit library is becoming "Develop" and Community Cloud is becoming "Deploy."

🧠 Description of Changes

• Rearrange docs under Streamlit library under the category of "Develop"
• Sort Advanced features, moving reference material to "API reference" and grouping the rest under "Concepts"
• Make Community Cloud a child under "Deploy"
• Explain fundamental concepts within the first child of "Deploy"

🌐 References

Notion Project: Docs: Information Architecture

Closes #462

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