[lldb] [llvm] [lldb] Add release note for SymStore and generate settings docs (PR #209469)

[David Spickett via llvm-commits]

DavidSpickett wrote:

@weliveindetail is best placed to say if it's informative enough I think.

I assume this is to land on main then be backported to 23 since it just missed the branch.

https://github.com/llvm/llvm-project/pull/209469