doc:update index.md

[ningmingxiao]

index.md is too old and it is different from readme.md.

[openshift-ci]

Hi @ningmingxiao. Thanks for your PR.

I'm waiting for a coreos member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[gemini-code-assist]

Code Review

This pull request provides a great update to the main documentation page. The changes include updating a link to the libostree documentation, replacing an outdated ASCII diagram with a much clearer and more maintainable Mermaid flowchart, adding an important note about the project's current development focus, and clarifying the features list. These updates significantly improve the accuracy and readability of the documentation for users. The new diagram and the clarification on OS rollback behavior are particularly valuable. Overall, this is an excellent set of improvements.

[cgwalters]

Thank you!

[ningmingxiao]

but I find https://coreos.github.io/rpm-ostree/ can't view picture @cgwalters