Add Release notes

Author: muqiuhan

docs/release-notes/.FSharp.Compiler.Service/10.0.200.md

@@ -8,3 +8,7 @@
 * `SynExprLetOrUseTrivia` is now `SynLetOrUseTrivia`. ([PR #19090](https://github.com/dotnet/fsharp/pull/19090))
 * `SynMemberDefn.LetBindings` has trivia. ([PR #19090](https://github.com/dotnet/fsharp/pull/19090))
 * `SynModuleDecl.Let` has trivia. ([PR #19090](https://github.com/dotnet/fsharp/pull/19090))
+
+### Changed
+
+* Improve rich diagnostic formatting. ([PR #19141](https://github.com/dotnet/fsharp/pull/19141))