Redesign Home Page

[wei]

After #68, Redesign home page to include some more examples for users to click on and get started.

[KemingHe]

Hi @wei, I know we still have a lot (of PRs) to work through, but just throwing some ideas out there: are we looking at something like the sample prompts for an ai chatbot, i.e.

Obviously ours will feature popular repos and maybe include their corresponding social preview generated by Socialify?