[llvm] [Docs][DebugInfo][RemoveDIs] Document some debug-info transition info (PR #79167)

[J. Ryan Stinnett via llvm-commits]

jryans wrote:

> the title of [llvm.org/docs/RemoveDIsDebugInfo.html](https://llvm.org/docs/RemoveDIsDebugInfo.html) is "What’s all this then?" which is not obvious what it refers to at a quick glance. could the title be more desriptive?

I opened https://github.com/llvm/llvm-project/pull/81480 to revise the title.

https://github.com/llvm/llvm-project/pull/79167