Update documents, Bump version to 2.4.1, Sync Fabric till 088cfb98

[Li Jiang (thinkall)]

Why are these changes needed?

• Update documentation to reflect recent changes, add best-practice guidance, and address common community FAQs.
• Bump version to 2.4.1.
• Sync Fabric to commit 088cfb98.

Related issue number

Checks

• I've used pre-commit to lint the changes in this PR (note the same in integrated in our CI checks).
• I've included any doc changes needed for https://microsoft.github.io/FLAML/. See https://microsoft.github.io/FLAML/docs/Contribute#documentation to build and test documentation locally.
• I've added tests (if relevant) corresponding to the changes introduced in this PR.
• I've made sure all auto checks have passed.