update onnxruntime docs, sync CANN quick start from upstream at build…

[bachelor-dou]

Summary

This PR adds ONNX Runtime-specific documentation sync so the CANN quick start stays aligned with upstream automatically during docs build.

Changes

• Added a dedicated ONNX Runtime sync target (sync-onnxruntime-doc) in build flow.
• Fetches latest official CANN Execution Provider quick-start markdown during build.
• Uses generated docs path for synced ONNX Runtime quick-start content.
• Updated ONNX Runtime quick-start entry/link to point to generated synced output.
• Removed the locally maintained ONNX Runtime quick-start source to prevent content drift.
• Added a minimal ONNX Runtime quickstart readability enhancement hook.

Why

Manual maintenance caused drift from upstream and created extra update overhead.
Build-time sync keeps ONNX Runtime quick-start content current with minimal maintenance.

Scope

Only ONNX Runtime quick-start documentation flow is affected.
No functional changes to other project docs.

[ascend-robot]

CLA Signature Pass

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

[zheliuyu]

After running make, I encountered the following error. It could be an issue with the specified path or a problem with the build files. I'll try again later.

[zheliuyu]

After rebuilding, it appears that the automatic documentation generation is unaffected.