feat: Implement configurable independent community sub-sites with modular navigation base on verl

[justbin-coder]

verview
This PR introduces a generic, highly extensible solution for "independent community sub-sites". Using the verl community as the first use case, it achieves sidebar content isolation, modular navigation based on the developer journey, and dynamic extraction of in-page TOCs for long documents. Future communities can be onboarded seamlessly by simply updating a configuration dict without any code changes.

Core Modifications

• conf.py: Added the independent_communities dictionary and an update_page_context hook to intercept paths during build and dynamically inject community configs to the frontend.
• _templates/layout.html: Utilized JS to dynamically reconstruct the DOM. It extracts the current community's directory tree, generates native-compliant category captions, and smartly elevates deep TOC levels to display inner headings.
• _static/custom.css: Added dedicated styles for #independent-sidebar, perfectly inheriting the active highlights and collapsible interactions of the native Sphinx RTD theme.
• Doc Source Files: Optimized the inclusion method for long documents (using MyST include) to resolve duplicate H1 conflicts and blank rendering issues.

Testing & Effects

• Navigation Isolation: Navigating to the verl community exclusively displays its own documents in the left sidebar, successfully hiding global unrelated content.
• Modular Categorization: The sidebar correctly categorizes items into modules like "Getting Started", "Application Guide", etc.
• Long Document Experience: When opening long Markdown documents (e.g., Ascend Performance Analysis Guide), its inner H2/H3 headings correctly expand and track active highlights in the left sidebar, with the main content rendering completely on the right.

[ascend-robot]

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[ascend-robot]

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[ascend-robot]

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[ascend-robot]

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justbin-coder, thanks for your pull request. All authors of the commits have signed the CLA. 👍

[ascend-robot]

CLA Signature Pass

justbin-coder, thanks for your pull request. All authors of the commits have signed the CLA. 👍

[ascend-robot]

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justbin-coder, thanks for your pull request. All authors of the commits have signed the CLA. 👍

[ascend-robot]

CLA Signature Pass

justbin-coder, thanks for your pull request. All authors of the commits have signed the CLA. 👍

[ascend-robot]

CLA Signature Pass

justbin-coder, thanks for your pull request. All authors of the commits have signed the CLA. 👍

[ascend-robot]

CLA Signature Pass

justbin-coder, thanks for your pull request. All authors of the commits have signed the CLA. 👍

[ascend-robot]

CLA Signature Pass

justbin-coder, thanks for your pull request. All authors of the commits have signed the CLA. 👍

[ascend-robot]

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justbin-coder, thanks for your pull request. All authors of the commits have signed the CLA. 👍

[justbin-coder]

[tardis-key]

What's in _static/ascend_config.json, such a huge change