docs: fix issues in HF integration docs

[prrao87]

• This PR addresses the issues in sidebar organization for the Hugging Face integration. Now, the HF docs should appear in two pages and are more clearly visible in the page at first glance.
• Remove redundant old sidebar link for huggingface.md (the doc source files come straight from the lance-format/lance-huggingface repo)

[github-actions]

Code Review

This PR looks good. The changes correctly:

1. Move the Huggingface docs copy step earlier in the workflow (before Spark/Ray)
2. Remove the stale static reference to huggingface.md from .pages since the content is dynamically copied from the lance-huggingface repo

No issues found. The sidebar ordering change should now reflect the intended documentation structure.