[llvm] [RemoveDIs][NFC] Update docs to reflect new class structure (PR #85109)

[J. Ryan Stinnett via llvm-commits]

https://github.com/jryans approved this pull request.

Looks great overall, thanks for working on this! 😄 

I've noted a few suggestions below, but none of them are blocking.

https://github.com/llvm/llvm-project/pull/85109