[clang] [Doc] Update documentation for no-transitive-change (PR #96453)

[Chuanqi Xu via cfe-commits]

================
@@ -229,6 +229,10 @@ C++20 Feature Support
   will now work.
   (#GH62925).
 
+- Clang refactored the BMI format to make it possible to support no transitive changes
----------------
ChuanqiXu9 wrote:

Good suggestions. Applied. (Just change `should` to `can`. Since I feel `should` read like users can get this benefit directly. But it is not the case. They need helps from build systems).

And I put this into the `What's New in Clang |release|?` section, which is highest except the `Potentially Breaking Change` section.

https://github.com/llvm/llvm-project/pull/96453