Guide to show how to port existing `kernels` incompatible builds to `kernels` compatible ones

[sayakpaul]

Consider having some kind of a guide that would show how to take a popular kernel source repo like flash-attn (or perhaps even something simpler) and how we made some changes to have it kernels compatible?

@hadarshxs, would you like to give this a try, especially since you recently did the SGLang port? Maybe we could also turn this into some kind of a skill so that agents like Claude Code can pick it up.