Separate Documentation Page for Custom Components

[freddyaboulton]

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Yesterday we discussed improving the documentation page for custom components. Writing down what I remember as the broad points of our brainstorm to kick this off. Let's synch on this this week @pngwn @aliabd

• Split up the Docs into two parts - the current part for gradio app authors and a new section for custom component authors.
• There are some internal utils/functions that are not documented anywhere. Like image saving utils. Let's document those in this new section.
• Imo we also really need #6226. We also need to explain some key frontend concepts since they aren't explained/documented anywhere -<Block, <StatusTracker, etc

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[abidlabs]

We should also document @server, as mentioned here: https://github.com/gradio-app/gradio/issues/6674