[clang] [docs] [C++20] [Modules] Ideas for transitioning to modules (PR #80687)

[David Blaikie via cfe-commits]

https://github.com/dwblaikie commented:

Generally seems like good stuff to write down - I'm not sure about the ABI breaking version (that mostly seems like it would make more problems than solutions).

Commented on some minor grammatical issues.

https://github.com/llvm/llvm-project/pull/80687