Update release notes

Author: brianrourkeboll

docs/release-notes/.FSharp.Compiler.Service/10.0.100.md

@@ -1,3 +1,7 @@
 ### Fixed
 
 * Allow `let!` and `use!` type annotations without requiring parentheses ([PR #18508](https://github.com/dotnet/fsharp/pull/18508))
+
+### Added
+
+* Add support for `when 'T : Enum` library-only library-only static optimization constraint. ([PR #18546](https://github.com/dotnet/fsharp/pull/18546))

docs/release-notes/.FSharp.Core/10.0.100.md

@@ -0,0 +1,10 @@
+### Fixed
+
+### Added
+
+* Enable more `string` optimizations by adding `when 'T : Enum` library-only library-only static optimization constraint. ([PR #18546](https://github.com/dotnet/fsharp/pull/18546))
+
+### Changed
+
+### Breaking Changes
+